JP3712688B2 - Hydraulic control device mounting structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mounting structure for a hydraulic control device used in a hydraulic control system in a construction machine such as a hydraulic excavator or a hydraulic crane.
[0002]
[Prior art]
Conventionally, a multi-type hydraulic control system has been adopted in many construction machines such as a hydraulic excavator and a hydraulic crane. This system supplies pressurized fluid discharged from one oil pump to a plurality of hydraulic control devices, and drives actuators connected to the respective hydraulic control devices.
[0003]
Among the hydraulic control systems described above, those having a load sensing function are known (for example, see JP-A-6-58305). This load sensing function is as follows. A variable displacement type hydraulic pump is used in the hydraulic control system, and the highest pressure of the pressurized fluid supplied to each actuator (hereinafter referred to as the maximum load pressure PLS) is handled as a feedback control amount. The hydraulic pump is controlled so that the difference between the discharge pressure P of the hydraulic pump and the maximum load pressure PLS is constant.
[0004]
The hydraulic control device having the load sensing function is pressurized by a throttle that opens according to the pressure of a fluid supplied as a pilot pressure or a manual operation amount, and a compensator that controls a differential pressure before and after the throttle to be constant. And a check valve disposed between each fluid output port and each pump port. This check valve prevents the backflow of the pressurized fluid.
[0005]
FIG. 7 is a cross-sectional view showing an example of a hydraulic control device incorporating such a compensator, which was previously filed by the present applicant. As shown in the figure, the hydraulic control device 500 includes a main body 501, a spool valve 502, flow paths 503 to 509 intersecting with the spool valve 502, a pump port 510, tank ports 511 and 512, and a PLS port 513. And a regulating valve 515 urged downward in the figure by a spring 514 provided in the pressure chamber 519, relief valves 516 and 517, and a port A1 and a port B1 connected to an actuator (not shown). A restriction 518 is provided between the flow path 503 and the flow paths 504 and 505. The adjustment valve 515 includes a compensator 520 and a switching valve (not shown) provided in the compensator 520. The adjustment valve 515 is provided in a casing hole 521 provided in the main body 501.
[0006]
As shown in the figure, the spool valve 502 includes a plurality of small diameter portions and a notch portion that functions as a throttle. As the spool valve 502 slides to the left in the figure, the pump port 510 and the flow path 503 are communicated. As the sliding amount of the spool valve 502 increases, the opening of the variable orifice formed in the spool valve 502 increases, and a large amount of hydraulic oil flows.
[0007]
Further, as the spool valve 502 slides, the flow path 505 and the flow path 507 are communicated, and the flow path 506 and the flow path 508 are communicated. The flow path 508 is connected to the tank port 512 and the relief valve 516. Further, the flow path 507 and the flow path 509 are blocked before and after the spool valve 502 slides, and the flow path 504 and the flow path 506 are blocked.
[0008]
Therefore, when the spool valve 502 is slid to the left in the figure, the hydraulic oil supplied to the pump port 510 is transferred to the port A1 via the flow path 503, the throttle 518 of the adjustment valve 515, the flow path 505, and the flow path 507. Supplied. The port A1 is connected to an actuator (not shown). The hydraulic oil returning from the actuator to the port B1 is discharged to the tank port 512 through the flow path 506. When a sudden high pressure is generated, the relief valve 517 operates to prevent the spool valve 502 or the like from being broken.
[0009]
Further, the spool port 502 is slid to the right side in the drawing, whereby the pump port 510 and the flow path 503 are communicated. As the sliding amount of the spool valve 502 increases, the opening of the variable orifice formed in the spool valve 502 increases and a large amount of hydraulic oil is supplied.
[0010]
As the spool valve 502 slides, the flow path 504 and the flow path 506 communicate with each other, and the flow path 507 and the flow path 509 communicate with each other. The flow path 509 is connected to the tank port 511 and the relief valve 517. Further, the flow path 505 and the flow path 507 are blocked before and after the spool valve 502 slides, and the flow path 506 and the flow path 508 are blocked. The flow path 509 is connected to the tank port 511 and the relief valve 517.
[0011]
When the spool valve 502 is slid to the right side in the drawing, the hydraulic oil supplied to the pump port 510 is supplied to the port B1 via the flow path 503, the throttle 518 of the adjustment valve 515, the flow path 504, and the flow path 506. The The port B1 is connected to an actuator (not shown). The hydraulic oil returning from the actuator to the port A1 is discharged to the tank port 511 via the flow path 507. Note that when a sudden high pressure is generated, the relief valve 516 operates to prevent the spool valve 502 or the like from malfunctioning.
[0012]
The hydraulic control device 500 configured as described above includes a maximum load pressure port (PLS port) 513 communicating with the pressure chamber 519 and a regulating valve 515 urged downward in the drawing by a spring 514 provided in the pressure chamber 519. The compensator 520 and the compensator 520 are slidably guided in the vertical direction of the drawing. Warehouse The sleeve 521 is provided. By attaching the sleeve 521 to the main body 501, the compensator 520 is disposed at a predetermined position.
[0013]
[Problems to be solved by the invention]
As described above, in the case of a hydraulic control device having a load sensing function, the compensator 520 descends as shown in the figure and is located between the flow path 503 and the flow paths 504 and 505 below the casing hole 521 formed in the main body 501. This is a structure in which the cross-sectional area is changed by a throttle 518 and hydraulic control is performed. In addition, the locking portion 522 formed in the compensator 520 is in close contact with the main body 501, and has a function as a check valve that prevents the backflow by stopping the oil flow by completely closing the gap of the throttle 518. are doing. Therefore, the radial gap between the compensator 520 and the casing hole 521 of the main body 501 is formed small.
[0014]
On the other hand, this compensator 520 is Warehouse The upper portion of the sleeve 521 is attached to the main body 501. For this reason, if the shaft center is displaced when the sleeve 521 is attached to the main body 501, the sleeve 521 is attached in a state in which the axial centers of the compensator 520 and the casing hole 521 of the main body 501 are displaced. Further, the deviation of the axial center cannot completely eliminate the manufacturing error of the axial center even if the sleeve 521 is attached to the main body 501 while keeping the gap between the compensator 520 and the casing hole 521 constant. For this reason, a deviation in the axial center may further occur due to a manufacturing error in the axial center.
[0015]
When mounted in a state in which the axial center is shifted in this way, when the compensator 520 is completely closed and functions as a check valve, the locking portion 522 of the compensator 520 is non-uniformly intended to be in close contact with the main body 501. There is a risk of force acting. In addition, stable close contact may be difficult.
[0016]
Therefore, the sealing performance of the check valve may be deteriorated, and oil leakage may occur when a large load is applied. In particular, in a construction machine such as a hydraulic excavator, there is a possibility that a boom may fall off when the load is held in a supported state, which may impair work stability.
[0017]
Further, one-side contact occurs on the outer periphery of the lower end of the compensator, the smooth movement of the compensator is hindered, and there is a risk that hysteresis will occur in the compensator performance.
[0018]
An object of the present invention is to allow a compensator having a load check function to be slidable. Warehouse Another object of the present invention is to provide an attachment structure that can attach a hydraulic control device including a sleeve to a main body in a state having a centering function.
[0019]
[Means for Solving the Problems]
Therefore, in order to achieve the above object, the hydraulic control device mounting structure according to the present invention detects the maximum load pressure of the actuator controlled by the variable displacement pump, and is higher by a predetermined value than the detected maximum load pressure. In the hydraulic control device having a load sensing function for controlling the discharge pressure of the variable displacement pump, the inlet flow passage communicating with the pump port of the variable displacement pump is connected to the outlet flow passage connected to the actuator. A compensator having a throttle that changes the amount of opening between it and the main body to control the pressure of the flowing oil, a sleeve that houses the compensator so as to be slidable in the direction of the throttle, and a bowl-shaped step formed on the sleeve A cover member for attaching the part to the main body, and a fluid from the outlet side flow path connected to the actuator to the pump port A check valve for blocking the reverse flow is formed integrally with the compensator between the inlet-side flow path and the outlet-side flow path, and the valve seat of the check valve is provided in the main body of the hydraulic control device. When the sleeve is attached, when the compensator is brought into close contact with the main body by the check valve and the throttle is closed, a gap in which the axial center position of the sleeve can move in the radial direction is provided between the sleeve and the sleeve mounting portion of the cover member and the main body And the axial movement of the sleeve is restricted within a predetermined range and the sleeve It is comprised so that a clearance gap may be maintained between the bowl-shaped step part of this, and a main body. As a result, when the compensator closes the throttle so as to shut off the flow path communicating with the pump port and the flow path connected to the actuator, the axial position of the sleeve moves so that the compensator is evenly in close contact with the main body. Therefore, the diaphragm can be stably closed by absorbing the deviation of the axial center.
[0020]
Moreover The compensator can have a check valve function.
[0021]
Also , Su The axis position of the leave is In the radial direction Movable gap Among range Move on It can be moved to close the throttling by bringing the compensator into close contact with the body.
[0022]
Further, in the mounting structure of the hydraulic control device, a sealing material that seals oil in a radial direction between the sleeve and the main body is provided, and the sealing material can be deformed in the radial direction between the sleeve and the cover member. If a gap in the range is provided, the sleeve moves through the gap in the range where the sealant can be deformed while maintaining the sealing performance between the sleeve and the main body, and absorbs the deviation of the axial center between the compensator and the main body. Thus, the throttle can be closed.
[0023]
Further, in such a mounting structure of the hydraulic control device, if the height of the cover member is formed to be higher than the protruding amount from the main body of the sleeve, during the transportation of the hydraulic control device and the installation work to the machine, Alternatively, it is possible to prevent an object from coming into contact with the sleeve during piping work, and to prevent the mounting position of the sleeve from going wrong.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a hydraulic system diagram showing an example of a hydraulic control system to which a mounting structure for a hydraulic control apparatus according to the present invention is applied. FIG. 2 is a cross-sectional view showing a hydraulic control apparatus employing the mounting structure according to the first embodiment of the present invention. FIG. 3 is a sectional view showing an operating state of the regulating valve in the hydraulic control apparatus. FIG. 4 is a cross-sectional view exaggerating the main portion for explaining the mounting structure of the hydraulic control device. FIG. 1 illustrates an example of a hydraulic control device used in a multiple hydraulic control system. In FIG. 4, the internal structure is omitted.
[0025]
First, based on FIG. 1, the structure of the multiple hydraulic control system 1 using the hydraulic control devices 100, 200, 300 according to an embodiment to which the present invention is applied will be described.
[0026]
As shown in the drawing, an oil supply line 50 extending from the variable displacement pump control unit 10 is connected to pump ports 120, 220, and 320 of the hydraulic control devices 100, 200, and 300. The tank ports 121, 221, and 321 of the hydraulic control devices 100, 200, and 300 are connected to the oil discharge tank 16 via the oil discharge line 51. The maximum load pressure PLS port (hereinafter referred to as “PLS port”) 183, 283, 383 of each hydraulic pressure control unit 100, 200, 300 is connected to the PLS line 18. The PLS line 18 is connected to the input unit 20 of the variable displacement pump control unit 10. The input unit 20 is configured to receive a maximum load pressure PLS.
[0027]
A throttle valve 21 is provided in the PLS line 18. In order to control the pressure acting on the switching valves 103, 203, 303, the throttle valve 21 always causes a flow of pressurized oil (hereinafter referred to as “hydraulic oil” as appropriate) in the circuit. Is. The throttle valve 21 returns a small amount of hydraulic oil (about 1%) out of the hydraulic oil flowing in the circuit to the oil discharge tank 16. The throttle valve 21 can also be provided as a structure having a similar function in a switching valve (hereinafter referred to as “switching valve”) 14 for controlling the tilt of the variable displacement pump.
[0028]
The variable displacement pump control unit 10 uses the value of the maximum load pressure PLS input to the input unit 20 as a feedback control amount, and the difference between the value of the maximum load pressure PLS and the discharge pressure P of the variable displacement pump 11 ( The discharge pressure P of the variable displacement pump 11 is controlled so that the reference differential pressure Pref) is always constant.
[0029]
The variable displacement pump control unit 10 includes a variable displacement pump 11, a tilt control device 13, a switching valve 14, and a tank 15.
[0030]
The variable displacement pump 11 includes a feedback lever 12. The feedback lever 12 is operated in a counterclockwise direction in the drawing to reduce the discharge amount. The upper end of the feedback lever 12 is connected to the control rod of the tilt control device 13. This control rod is provided with a spring 13a.
[0031]
The control rod of the tilt control device 13 has a rightward force in the figure by the pressure in the branch pipe of the oil supply line 50, a leftward force in the figure by the pressure guided from the lower port 14a of the switching valve 14, and a spring force. Works. Therefore, the control rod moves left and right by the interaction of the forces.
[0032]
The switching valve 14 has three ports and can be switched to two states. The switching valve 14 is switched according to the relationship (strength) between the force based on the discharge pressure P of the variable displacement pump 11 and the force based on the pressure (PLS + Pref) obtained by adding a predetermined reference pressure Pref to the maximum load pressure PLS. It is supposed to change.
[0033]
The switching valve 14 includes a spring corresponding to the pressure Pref. When the discharge pressure P of the variable displacement pump 11 is higher than the pressure (PLS + Pref), the switching valve 14 is switched to the connection state on the left side in the figure. Then, the hydraulic oil discharged from the variable displacement pump 11 is sent to the right port of the tilt control device 13, and the control rod of the tilt control device 13 moves to the left in the figure. As a result, the feedback lever 12 of the variable displacement pump 11 moves counterclockwise, and the discharge amount of the variable displacement pump 11 decreases.
[0034]
On the other hand, when the pressure (PLS + Pref) is higher than the discharge pressure P, the switching valve 14 switches to the connection state on the right side in the figure. Then, the hydraulic oil is discharged from the right port of the tilt control device 13 into the tank 15 and the control rod of the tilt control device 13 moves to the right. As a result, the feedback lever 12 of the variable displacement pump 11 moves clockwise, and the discharge amount of the variable displacement pump 11 increases.
[0035]
By such an operation of the switching valve 14, the difference between the maximum load pressure generated in the PLS line 18 and the discharge pressure P discharged from the variable displacement pump 11 is always maintained at a predetermined reference value Pref.
[0036]
The configuration of each hydraulic control device 100, 200, 300 shown in FIG. 1 is the same. Only the hydraulic control device 100 will be described below.
[0037]
The hydraulic control device 100 is roughly composed of a spool valve 101 and an integrated hydraulic adjustment valve (hereinafter referred to as “regulation valve”) 110.
[0038]
The spool valve 101 opens the variable orifices 101a and 101b according to the sliding amount, and outputs the hydraulic oil supplied to the pump port 120 to the adjustment valve 110 via the variable orifices 101a and 101b. Further, the spool valve 101 outputs the hydraulic oil output from the adjustment valve 110 to the port A1 or the port B1 in accordance with the slide direction (left and right).
[0039]
The regulating valve 110 includes a compensator 102 and a switching valve 103. The compensator 102 has two ports and can switch between two states.
[0040]
The switching valve 103 is disposed inside the compensator 102. The switching valve 103 has four ports and can switch between two states. The switching valve 103 functions independently of the compensator 102.
[0041]
The compensator 102 operates according to the level of the total pressure shown below (PLS + F / S or P31 + F / S; where S is the area of the working surface and F is the elastic force of the spring 165). By operating the compensator 102, the opening area of the throttle (compensating portion) 159 is controlled, and the pressure P21 of the hydraulic oil supplied to the regulating valve 110 is controlled. Here, the total pressure is the total pressure of the maximum load pressure PLS selected and output by the switching valve 103 and the spring 165 (see FIG. 2), or the outlet flow paths 131 and 132 (see FIG. 2). This pressure is the total of the pressure added by the elastic force F of the spring 165 provided in the adjustment valve 110 to the internal pressure P31.
[0042]
When the pressure P21 is equal to or lower than the total pressure (PLS + F / S), the pressure P21 acts in a direction in which the gap between the input port 102a (input side flow path) and the output port 102b (output side flow path) is closed. As a result, the opening area is reduced, and control is performed so that P21 = (PLS + F / S). That is, in the figure, the diaphragm 159 is in a state of being narrowed.
[0043]
When the pressure P21 is higher than the total pressure (PLS + F / S), the input port 102a is connected via a throttle 159 and a check valve 159a (annular locking portion) that open according to the value of the pressure P21. Connected to the output port 102b. At this time, the opening of the diaphragm 159 becomes large, and P21 = (P31 + F / S).
[0044]
The switching valve 103 is switched according to the level of the maximum load pressure PLS guided to the PLS port 183 and the hydraulic oil pressure P31 output from the output port 102b of the compensator 102.
[0045]
When the maximum load pressure PLS is higher than the pressure P31, a line extending from the PLS port 183 is connected to the input unit 102c of the compensator 102. On the other hand, when the maximum load pressure PLS is lower than the pressure P31, the hydraulic oil (pressure P21) supplied to the regulating valve 110 is supplied to the maximum load pressure PLS port 183. Further, as will be described later, the pressure P21 is reduced to a pressure equivalent to the pressure P31. Thereby, the maximum load pressure PLS in the hydraulic control system 1 is updated to the pressure P31, and the pressure P31 becomes the maximum load pressure PLS. Further, a line extending from the output port 102 b of the compensator 102 is connected to the input unit 102 c of the compensator 102.
[0046]
Next, the operation of the hydraulic control device will be described with reference to FIG. As shown in the figure, the main body 105 of the hydraulic control device 100 includes a first cylinder portion 106a having a diameter D1, a depth L1, a second cylinder portion 106b having a diameter D2, a depth L2, and a first cylinder portion having a diameter D3 and a depth L3. Three cylinder portions 106c are continuously provided on the same axis. A casing hole 106 is formed by these first to third cylinder portions. A maximum load pressure PLS port (hereinafter referred to as “PLS port”) 183 is provided on the side of the first cylinder portion 106a. The connecting portion from the first cylinder portion 106a to the second cylinder portion 106b is processed into a taper shape. A step is provided at the connecting portion between the second cylinder portion 106b and the third cylinder portion 106c. An opening connected to the flow channel 131 and the flow channel 132 is provided on the lower side surface of the second cylinder portion 106b.
[0047]
A sleeve 170 provided in the casing hole 106 of the main body 105 includes an adjustment valve 110 inside. Warehouse In addition, it is formed in a substantially cylindrical shape having a diameter D2 having an opening below. An airtight space is formed by the sealing material 173 and the sealing material 174 between the sleeve 170 and the first cylinder portion 106 a and the second cylinder portion 106 b of the main body 105. These sealing materials 173 and 174 seal between the main body 105 and the sleeve 170.
[0048]
The sleeve 170 has a through hole 172 in the small diameter portion 171. The through hole 172 is provided on a surface that partitions the airtight space. The maximum load pressure PLS supplied to the PLS port 183 is guided to the inside of the sleeve 170 through the through hole 172.
[0049]
A communication groove 152 extends in the axial direction from the appropriate portion of the small diameter portion 153 communicating with the through hole 172 in the adjustment valve 110. The lateral hole 151 is provided so as to intersect with the communication groove 152. The hole 154 is provided sideways so as to intersect with the holes 156 that communicate with the holes 151 and 150 and the aperture 159. The cylindrical small diameter portion 153 of the adjustment valve 110 is provided at least in a range where the adjustment valve 110 always communicates with the through-hole 172 of the sleeve 170 even when the adjustment valve 110 moves up and down.
[0050]
The compensator 102 of the regulating valve 110 is constituted by a cylindrical piston having a diameter of D4, and a throttle 159 having a diameter of D3 is provided below the piston. By opening / closing the restrictor 159, the flow path 130 (input side flow path), the flow path 131, and the flow path 132 (output side flow path) communicate with each other. The opening area of the throttle 159 increases as the adjustment valve 110 rises.
[0051]
A notch 160 and a flow path 161 are provided on the side of the compensator 102. These communicate the flow path 132, the flow path 131, and the hole 154.
[0052]
In the compensator 102 in this embodiment, the diameter D4 part and the diameter D3 part have the same diameter, and a locking part 157 having a diameter larger than the diameter D3 is formed on the upper portion of the diaphragm 159 having a diameter D3. The locking portion 157 is an annular protrusion and is integrally provided on the upper portion of the diaphragm 159. As shown in the drawing, the locking portion 157 is processed into a taper shape whose diameter increases toward the upper side, and is designed to come into contact with the upper end corner of the third cylinder portion having a diameter D3 of the main body 105. .
[0053]
The maximum pressure PLS in the hydraulic control system 1 is supplied to the pressure chamber 164 of the sleeve 170 from the PLS port 183 or the flow paths 130, 131, and 132. In this figure, the pressure of the PLS port 183 is acting on the pressure chamber 164. Therefore, the compensator 102 has a force PLS × SD4 generated when the maximum load pressure PLS acts (where SD4 is the area of the upper surface of the diameter D4 of the regulating valve 110 where the maximum load pressure PLS acts). The spring 165 is biased downward by a force (PLS × SD4 + F) obtained by adding the elastic force F of the spring 165 determined according to the above.
[0054]
Further, the regulating valve 110 has a force P21 × SD3 (where P21 is the pressure in the flow path 130. SD3 is the pressure on the lower surface of the diameter D3 of the regulating valve 110 on which the pressure P21 acts) due to the hydraulic oil in the flow path 130. The area is biased upward.
[0055]
The side portion of the compensator 102 of the regulating valve 110 is completely between the flow path 130 and the flow paths 131 and 132 in a state where the locking portion 157 is in contact with the step portion of the second cylinder portion and the third cylinder portion. It is long enough to occlude. An upper end corner of the third cylinder portion of the main body 105 that is in close contact with the locking portion 157 is formed in a conical seal portion 107.
[0056]
When the locking portion 157 of the compensator 102 is in close contact with the seal portion 107 of the main body 105, the space between the flow path 130 and the flow paths 131 and 132 is closed. This functions as the check valve 159a, and the state where the throttle 159 is closed is the seal state of the check valve 159a.
[0057]
When the pressure in the flow path 130 is lower than the pressure in the flow path 132 and the flow path 131, the locking portion 157 blocks the flow path 130 from the flow path 131 and the flow path 132, and The hydraulic oil is prevented from flowing backward from the passage 132 to the passage 130. At this time, the conical seal portion 107 formed at the upper corner of the third cylinder portion functions as a valve seat for the check valve.
[0058]
The restrictor 159 has a constant differential pressure between the front and rear, that is, the difference between the pressure P21 of the hydraulic oil flowing in the flow path 130 (input side flow path) and the pressure P31 of the flow paths 131 and 132 (output side flow path). Work to be.
[0059]
In FIG. 2, since the neutral state is shown, the flow paths 131 and 132 are not in communication with the flow paths 133 and 134. The switching valve 155 (103 in FIG. 1) in this figure is in a state where it has moved to the right end in the figure when the maximum load pressure PLS of another series is supplied to the left chamber illustrated in the hole 154. On the other hand, the hydraulic oil in the flow path 132 is supplied to the room on the right side of the hole 154 illustrated through the notch 160 and the flow path 161. As a result, the switching valve 155 moves to the left and right in the figure according to the pressure magnitude relationship. As described above, the switching valve 155 operates independently of the throttle 159.
[0060]
The switching valve 155 is accommodated in the hole 154 so as to slide left and right in an airtight state. The hole 150 intersects with the hole 154 and is provided vertically so as to communicate with the pressure chamber 164. The hole 156 intersects with the hole 154 and is provided vertically so as to communicate with the flow path 130. Further, the left sides of the holes 151 and 154 communicate with each other through an annular groove provided on the outer periphery of the compensator 102.
[0061]
On the other hand, the upper portion of the sleeve 170 is provided with a bowl-shaped step 176 for attaching to the main body 105. The sleeve 170 accommodating the regulating valve 110 is inserted into the casing hole 106 provided in the main body 105, and the upper bowl-shaped step 176 is attached to the main body 105 by the cover member 175. Reference numeral 177 denotes a mounting bolt.
[0062]
As described above, the diameter D3 and the diameter D4 of the compensator 102 have the same diameter, and the large-diameter engaging portion 157 is formed between them, so that the compensator 102 is first built in the sleeve 170. The sleeve 170 is attached to the main body 105.
[0063]
FIG. 3 is a cross-sectional view showing the state of the regulating valve when the maximum load pressure of another series is high, and shows the state of the switching valve 155 when the maximum load pressure PLS is higher than the pressure P31 of the flow path 132. It is.
[0064]
In this case, the hole 156 provided on the throttle 159 is closed by the switching valve 155, and the hydraulic oil supplied via the PLS port 183 (the pressure of this hydraulic oil is the maximum load pressure PLS) It will be guided to the pressure chamber 164 through the hole 150.
[0065]
In this case, the adjustment valve 110 is actually raised so as to adjust the opening amount of the throttle 159 by an amount corresponding to the magnitude of the pressure P21 in the flow path 130. That is, the opening amount of the restrictor 159 is adjusted so that the pressure of the pressure chamber 164 balances the force of the oil acting on the adjustment valve 110 and the combined force of the springs 165. That is, as shown in the figure, the compensator 102 slides upward, the locking portion 157 rises from the seal portion 107 of the main body 105 by a predetermined amount, and hydraulic oil that has been throttled from the flow path 130 to the flow path 131 is supplied. Will be.
[0066]
As described above, pressure adjustment is performed according to the opening amount of the diaphragm 159.
[0067]
FIG. 4 is a cross-sectional view exaggerating the main part for explaining the mounting structure of the hydraulic control apparatus according to the first embodiment of the present invention shown in FIG. As shown in the figure, the compensator 102 built in the sleeve 170 described above is provided in the sleeve 170 so as to be slidable in the direction (the vertical direction shown in the figure) to open and close the throttle 159 with the seal portion 107 of the main body 105. It has been. The sleeve 170 is inserted into the casing hole 106 provided in the main body 105, and the oil from the flow paths 131 and 132 and the first cylinder portion 106a is sealed by sealing members 173 and 174 provided at the upper and lower sides of the periphery. Is leaking to the cover member 175 side. Between the sleeve 170 and the casing hole 106, a clearance Sc that can be sealed with the sealing materials 173 and 174 is provided. This gap Sc indicates a smaller one of the diameter D1 part and the diameter D2 part, and is a range in which the sealing materials 173 and 174 can be deformed while maintaining the sealing performance.
[0068]
The sleeve 170 is attached in a state where predetermined gaps Sa and Sb are provided between the sleeve 170 and the cover member 175 attached to the main body 105. The gaps Sa and Sb are provided in the radial direction and the axial direction of the flange-shaped step portion 176 of the sleeve 170, the gap Sa is provided in the radial direction, and the gap Sb is provided in the axial direction. The radial gap Sa is in a range in which the sealing materials 173 and 174 provided between the sleeve 170 and the casing hole 106 can be deformed while maintaining sealing performance. The axial center of the sleeve 170 is movable within the range of the clearance Sa. The gap Sa has a dimension that can absorb the deviation of the axial center between the axial center of the compensator 102 and the axial center of the third cylinder portion 106c of the main body casing hole 106. The axial gap Sb is a dimension that does not hinder the axial movement of the sleeve 170.
[0069]
In a state where the sleeve 170 is attached to the main body 105 with the cover member 175, the compensator 102 moves up and down and adjusts the opening area between the oil passage 130 and the oil passages 131 and 132 to adjust the pressure of the hydraulic oil 159. Open and close. When the locking portion 157 and the seal portion 107 are in close contact with each other so as to close the throttle 159, the locking portion 157 functions as a check valve 159a.
[0070]
In this state functioning as a check valve, the locking portion 157 of the compensator 102 is pressed against the seal portion 107 of the main body 105 by the oil pressure in the pressure chamber 164 and the force of the spring 165.
[0071]
At this time, as described above, the sleeve 170 attached by the cover member 175 is within the gap Sa of the cover member 175 so that the locking portion 157 of the compensator 102 is stably in close contact with the seal portion 107 of the main body 105. The axis is moved and aligned.
[0072]
That is, the sleeve 170 incorporating the compensator 102 is configured to be movable in the lateral direction (moving direction of the shaft center) within a predetermined gap Sa at the attachment portion of the cover member 175. The sleeve 170 can be moved within the range, and the sleeve 170 is moved and the coaxiality is adjusted so that the locking portion 157 of the compensator 102 pressed by the pressure of the hydraulic oil is evenly pressed.
[0073]
When the sleeve 170 is aligned in this way, the movement of the upper end of the sleeve 170 in the axial direction (vertical direction) is restricted at a predetermined position by the cover member 175, so that the gap Sb is maintained on the lower side. The upward movement is suppressed.
[0074]
Therefore, even if an axial misalignment occurs due to a manufacturing error between the seat portion 107 provided in the main body 105 and the locking portion 157 formed in the lower portion of the compensator 102, the main body 105 and the compensator 102 are caused by hydraulic pressure. An unreasonable force due to contact does not act between the locking portions 157, and the functions as a check valve can be exerted stably and stably.
[0075]
At this time, the sleeve 170 Warehouse The axial movement (slide) of the compensator 102 is also performed smoothly.
[0076]
FIG. 5 is a cross-sectional view schematically illustrating only the mounting structure of the hydraulic control device according to the second embodiment of the present invention, and FIG. 6 is a perspective view of the mounting structure of the hydraulic control device viewed obliquely from above. It is a perspective view. In FIG. 5, the internal structure is omitted. This 2nd Embodiment is embodiment from which the cover member 175 in 1st Embodiment mentioned above differs. In addition, since the other structure is the same as 1st Embodiment mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
[0077]
As shown in the drawing, the cover member 178 in this embodiment is formed with a height hc higher than the protruding amount hs of the sleeve 170. Since other configurations are the same as those of the first embodiment described above, detailed description thereof is omitted.
[0078]
By providing such a cover member 178, it is possible to prevent an object from coming into contact with the sleeve 170 during conveyance, installation work on a machine, or piping work, so that the mounting position of the sleeve 170 is out of order. Can be prevented.
[0079]
In addition, according to the attachment structure of these hydraulic control apparatuses comprised in this way, since the flow of hydraulic fluid is stabilized, stability of a load sensing function can be improved.
[0080]
The above-described embodiment is an embodiment, and various modifications are possible without departing from the scope of the present invention. The present invention is not limited to the above-described embodiment.
[0081]
【The invention's effect】
According to the hydraulic control apparatus of the present invention, the compensator is Warehouse Therefore, it is possible to provide a hydraulic control device capable of aligning and demonstrating a stable check valve sealing performance even if a deviation in axial center due to a manufacturing error or the like occurs. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a hydraulic system diagram showing an example of a hydraulic control system to which a mounting structure of a hydraulic control device of the present invention is applied.
FIG. 2 is a cross-sectional view showing a hydraulic control device employing the mounting structure according to the first embodiment of the present invention.
3 is a cross-sectional view showing an operating state of a regulating valve in the hydraulic control device shown in FIG. 2;
4 is a cross-sectional view exaggerating and illustrating essential portions for explaining the mounting structure of the hydraulic control device according to the first embodiment of the present invention shown in FIG. 2;
FIG. 5 is a cross-sectional view exaggerating a main part for explaining a mounting structure of a hydraulic control device according to a second embodiment of the present invention.
6 is a perspective view of the mounting structure of the hydraulic control device shown in FIG. 5 as viewed obliquely from above.
FIG. 7 is a cross-sectional view showing a configuration of a conventional hydraulic control device.
[Explanation of symbols]
1 ... Hydraulic control system
10 ... Pump
14 ... Switching valve
18 ... PLS line
100 ... Hydraulic control device
101 ... Spool valve
102 ... Compensator
103 ... switching valve
105 ... Body
106: Casing hole
107 ... seal part
110 ... Regulating valve
120 ... Pump port
130 ... flow path
131 ... flow path
132 ... Flow path
133 ... flow path
134 ... flow path
151 ... Horizontal hole
152 ... Communication groove
153 ... Small diameter part (regulating valve)
154 ... hole
155 ... Switching valve
156 ... hole
157 ... Locking part
159 ... Aperture
164 ... Pressure chamber
170 ... Sleeve
171 ... Small diameter part (sleeve)
172 ... hole
173, 174 ... Sealing material
175 ... Cover member
176 ... bowl-shaped step
177 ... Bolt
178 ... Cover member
183 ... PLS port
200 ... Hydraulic control device
300 ... Hydraulic control device
A1 ... Port
B1 ... Port
Sa, Sb ... Gap

Claims (3)

In a hydraulic control device having a load sensing function for detecting the maximum load pressure of an actuator controlled by a variable displacement pump and controlling the discharge pressure of the variable displacement pump so as to be higher than the detected maximum load pressure by a predetermined value ,
A compensator having a throttle that changes the amount of opening between the main body and the main body in order to control the pressure of oil flowing from the inlet-side passage communicating with the pump port of the variable displacement pump to the outlet-side passage connected to the actuator And a sleeve that houses the compensator so as to be slidable in the direction of the throttle, and a cover member that attaches a bowl-shaped step formed on the sleeve to the main body, and from the outlet flow path connected to the actuator, A check valve that blocks back flow of fluid to the pump port is formed integrally with a compensator between the inlet-side flow path and the outlet-side flow path, and the valve seat of the check valve is formed in the main body of the hydraulic control device. When the sleeve is mounted by the cover member, the axial position of the sleeve moves in the radial direction when the compensator is brought into close contact with the main body by the check valve to close the throttle. Provided with a capacity gap between the sleeve mounting portion and the main body of the cover member and the sleeve, a gap between the flange-like step portion and the main body of the to regulate the axial movement of the sleeve in a predetermined range sleeve A structure for mounting a hydraulic control device characterized by maintaining the pressure. In the mounting structure of the hydraulic control device according to claim 1 ,
Installation of a hydraulic control device provided with a sealing material that seals oil in a radial direction between the sleeve and the main body, and a gap in a deformable range of the sealing material in the radial direction between the sleeve and the cover member Construction. In the mounting structure of the hydraulic control device according to claim 1,
The mounting structure of the hydraulic control device, wherein the height of the cover member is higher than the protruding amount from the main body of the sleeve.

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