JPH0738699Y2 - Plunger pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a plunger pump in which a plurality of plungers are sequentially operated.

<< Prior Art >> A plunger pump is known, which pressurizes a plurality of plungers by an eccentric cam pivotally supported in a pump casing to pressurize a fluid at a high compression rate. No. 60-60370.

A radial plunger pump as shown schematically in FIG. 6 is shown therein. This radial plunger pump has an eccentric chamber 3 formed in a casing 1, and the casing 1 integrally connects a damping pot 4 on the discharge side. Plural plungers 5 are provided in the casing 1, and these are subjected to a pressing force by an eccentric ring 6 rotating in the eccentric chamber 3 to operate a pump, suck hydraulic oil from the eccentric chamber 3, and to dampen the damping pot 4
It works to discharge inside. Here, the pressurizing chamber 7 and the damping pot 4 are connected via a discharge passage 8 and a discharge valve 9.

In such a radial plunger pump, the plunger 5 is pressurized when the eccentric wheel 6 rotates, and the eccentric chamber 3 is added to the pressurizing chamber 7.
The hydraulic fluid sucked in is pressurized to discharge passage 8 and discharge valve 9
The high-pressure hydraulic oil is operated to be pressure-fed to the damping pot 4 via.

<< Problems to be Solved by the Invention >> By the way, in this radial plunger pump, a plurality of illustrated plungers 5 are arranged on the casing 1, and the hydraulic oil from each plunger 5 is discharged through the discharge passage 8 respectively.
And it is pressure-fed to the attenuation pot 4 via the discharge valve 9. Therefore, the same number of check valves as the plungers 5 are required as the discharge valves, and the number of constituent parts is large. In addition, it is necessary to maintain the processing accuracy of the mounting portion of each of these check valves at a predetermined level, and there is a problem that the cost is increased due to both of these factors.

Therefore, an object of the present invention is to provide a plunger pump in which the discharge valves that open and close the discharge passage are integrated and the configuration can be simplified.

<< Means for Solving the Problems >> In the plunger pump according to the present invention, a plurality of plungers are arranged in a pump casing, and a discharge chamber is formed so as to face the intermediate partition wall. Is a plunger pump in which each discharge passage for guiding the discharge passage to the discharge chamber is formed in each of the intermediate partition walls, and a valve seat surface formed by opening the discharge passages is formed in the intermediate partition wall. A single plate check valve having a plurality of tongue portions radially arranged so as to be capable of closing the openings of the respective discharge passages is provided, and the central portion thereof is fixed to the valve seat surface with a bolt, Is set so that the radius of the head is approximately the same as or longer than the length from the center of the bolt to the opening of each discharge passage, and the plate check valve is opened between the head and the valve seat surface. The tongue on the valve It is characterized in that a gap is formed to allow the shift amount.

<< Operation >> Each tongue piece of a single plate check valve closes the opening of each discharge passage and acts as a check valve, and the gap and head allow the lift amount of the tongue piece when opening. The bolt with a large radius acts as a stopper that restricts the excessive opening of the tongue, and this plate check valve has its central portion screwed to the valve seat surface, making it easy to install. good.

<< Embodiment >> FIG. 1 shows an example of a plunger pump according to the present invention, and FIG. 2 is a front view of a mounting portion of a plate check valve 10 which is a discharge valve.

This plunger pump is attached to a hydraulic circuit of a power steering (not shown), receives low-pressure oil on the side of an oil tank (not shown) in the circuit from the suction passage I side in the suction chamber 11, and receives high-pressure oil in the discharge chamber 12 on the discharge passage E side. To discharge.

The casing 13 of the plunger pump has a substantially annular shape, and has a shape in which the suction chamber 11 and the discharge chamber 12 therein are separated by an intermediate partition wall 14. A shaft 32 is pivotally attached to the inner peripheral wall of the suction chamber 11 via bearings 15 and 16. A pulley (not shown) is integrally coupled to the outer end of the shaft 32, and the rotational force of the engine (not shown) is transmitted to the pulley.
An eccentric cam 17 is bored in a portion of the shaft 32 opposed to the suction chamber 11, and six plungers 18 are arranged to face each other in the direction of the rotational trajectory of the cam.

Each of the plungers 18 is arranged long in the radial direction of the axis center line l, and is fitted into a plunger chamber 19 formed in the casing 13. The outer end side of the plunger chamber 19 is sealed by a plug plug 20 screwed to the casing 13, and a discharge passage 21 is formed so as to extend from the inner wall surface thereof.

The plunger chamber 19 is provided with a pin-shaped retainer 22 and a spring 31 between the retainer and the plunger 18. Therefore, the plunger 18 is pressed by the spring 31 from the pressurization position shown by the solid line in FIG. 1 to the suction position shown by the broken line, and at that time, from the suction hole 33 of the plunger to the plunger chamber 19
Let the oil inhale. When the eccentric cam 17 pushes the oil to the pressurizing position again, the oil in the plunger chamber 19 is discharged to the discharge path.
Pump to 21 side.

A discharge passage 21 extending from each plunger chamber 19 is bored in the intermediate partition wall 14, and each opening is collected and opened in the intermediate partition wall 14 on a flat valve seat surface 23 that is a surface facing the discharge chamber 12. Has been done. That is, as shown in FIG. 3, the openings of the six discharge passages 21 are arranged on an arc centered at the intersection of the axial center line 1 and the valve seat surface 23, and the opening surfaces of the oil passages are the same. The valve seat surface is continuously formed.

A threaded hole is formed in the center of the valve seat surface 23, and a bolt 30 is screwed into the threaded hole, whereby the central portion of the plate check valve 10 is fixed at one place.

As shown in FIG. 4, the plate check valve 10 is composed of an annular central portion 10b having a mounting hole 10a and six tongue pieces 10c extending radially from the central portion. It is formed of a plate material made of spring steel in the shape of a human hand. The check valve 10 is mounted so that the tongue portions 10c close the openings of the discharge passages 21 that face each other, and can receive high pressure oil from the discharge passage 21 side to elastically deform as shown in FIG. When the discharge passage 21 is in a low pressure state, it closes each opening and works to block the flow of oil from the discharge chamber 12 to the plunger chamber 19 side.

As shown in FIG. 1, the head portion 301 of the bolt 30 fixing the plate check valve 10 has a large diameter, and a concave hexagonal hole is formed in the head portion, and the head portion has a cylindrical shape. Has been formed. Moreover, the radius of the head portion 301 is set to be slightly shorter than the length of each tongue piece portion 10c. Further, as shown in FIG. 5, an inclined surface 303 is formed at the outer peripheral end of the valve seat surface 23 side of the head 301.
Are formed. Further, the surface of the bolt head 301 on the valve seat surface 23 side is stepped with a step h on the outer peripheral surface 302 with respect to the central portion in contact with the valve seat, and is formed between the head and the valve seat surface. A gap is formed to allow the lift amount of the tongue portion 10c when the plate check valve 10 is opened.

In FIG. 1, reference numeral 25 is a sealing plate having reinforced rigidity, which is fitted to seal the opening of the discharge chamber. In this case, the outward pressing force applied to the sealing plate 25 is received by the lock ring 26 fitted to the opening edge 101 of the casing 1,
It is transmitted to the casing 1 side. Further, a seal ring 27 is annularly attached between the opening edge 101 and the sealing plate 25, thereby ensuring airtightness.

The movement of the bearing 16 fitted on the inner wall of the suction chamber 11 is restricted by the lock ring 28. Moreover, the seal member 29 is press-fitted to the outer position of the lock ring, thereby preventing the low-pressure oil from leaking.

Such a plunger pump is driven to rotate together with the drive of the engine, and can secure high pressure oil in the hydraulic circuit of the power steering device. In this case, the six plungers 18 are sequentially pressed by the eccentric cam 17, and the pump is operated each time. As a result, high-pressure oil is discharged through each discharge passage 21, and one of the tongue pieces 10c facing each other in the plate check valve is opened and flows into the discharge chamber 12. In this way, the high-pressure oil that has passed through each tongue piece 10c from each discharge passage 21 and reached the discharge chamber 12 has its pressure smoothed in the discharge chamber 12 and is supplied to the discharge passage E side.

Here, as shown in FIG. 5, the step h of the bolt 30 that fastens and fixes the plate check valve 10 and the inclined surface 303 of the outer peripheral end.
Allows opening and closing of the tongue piece 10c. That is, the head 301 of the bolt 30 acts as a stopper that regulates the lift amount of the tongue piece 10c when the valve is opened. This prevents the tongue piece from being plastically deformed when an excessive hydraulic pressure is applied from the side of the discharge passage 21 and hindering the subsequent function as the check valve.

Such a plunger pump is configured so as to have a single function as a check valve that opens and closes each opening portion of the six discharge passages 21 by a single plate check valve 10. Therefore, the shape can be simplified, the mounting space can be reduced, the mounting workability can be improved, and the cost can be reduced. Since the head 30 has a large diameter, and a gap is provided between the head of the bolt and the valve seat surface 23 to allow the lift amount of the tongue portion 10c when the plate check valve 10 is opened, An advantage is that the tongue piece 10c is prevented from being plastically deformed when an excessive hydraulic pressure is applied from the discharge passage 21 side.

<Effects of the Invention> As described above, the plunger pump according to the present invention is configured so that the openings of the respective discharge passages are closed by the plurality of tongue portions radially arranged on the plate-like check valve. It becomes a plate check valve, and since the central part of this check valve is attached to the valve seat surface, each tongue piece independently operates as a check valve for each discharge passage, and prevents backflow of fluid. Nevertheless, the structure can be simplified, the number of parts can be reduced, the mounting can be facilitated, and the cost can be reduced. The radius of the head of the bolt that secures the check valve is set to be approximately the same as or longer than the length from the center of the bolt to each opening, and the plate-shaped reverse is provided between the head and the valve seat surface. Since a gap is provided to allow the lift amount of the tongue when the stop valve is opened, it prevents plastic deformation of the tongue and prevents the subsequent check valve from being hindered. There are advantages.

[Brief description of drawings]

1 is a sectional view of a plunger pump showing an embodiment of the present invention, FIG. 2 is a front view of the pump of FIG. 1 in the direction of arrow A, and FIG. 3 is a front view of a valve seat surface of the pump of FIG. Figure, 4th
1 is a front view of the plate-like check valve of the pump of FIG. 1, FIG. 5 is an explanatory view of the plate-like check valve of the pump of FIG. 1, and FIG. 6 is a schematic sectional view of the pump. 10 ... Plate check valve, 10a ... Central part, 10c ... Tongue part, 13 ... Casing, 14 ... Intermediate partition, 18 ... Plunger, 21 ... Discharge passage,
23… Valve seat surface, 24,30… Bolts, 12… Discharge chamber.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F04B 53/10 (56) References JP-A-59-218393 (JP, A) Actual development Sho-62- 105371 (JP, U) Japanese Patent Sho 61-15274 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A plurality of plungers are arranged in a pump casing, and a discharge chamber is formed so as to face the intermediate partition wall, and each discharge passage for guiding the fluid from each plunger to the discharge chamber is provided. A plunger pump formed in each of the intermediate partition walls, wherein a valve seat surface formed by opening each of the discharge passages is formed in the intermediate partition wall, and the opening of each of the discharge passages can be closed on the valve seat surface. A single plate check valve with a plurality of tongues arranged radially is provided, the central part of which is fixed to the valve seat surface with a bolt, and the bolt has a radius of the head from the center of the bolt. The length to the opening of each discharge passage is set to be approximately the same as or longer than the opening, and the lift amount of the tongue piece when the plate check valve is opened is allowed between the head and the valve seat surface. To form a gap that Njaponpu.