JP2001330008A - Four-position actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a four-position actuator with a simple structure enabling the diameters of a piston and a cylinder to be decreased. SOLUTION: Large diameter cylinders 3 and 7 are provided on both ends of a cylinder body 4, small diameter cylinders 4 and 6 are provided inside the large diameter cylinders 3 and 7, and large diameter parts of a pair of right and left stepped pistons 14 and 16 are fitted into the small diameter cylinders 4 and 6. The small diameter parts of the stepped pistons 14 and 16 are engaged with annular pistons 13 and 17 engaged with the large diameter cylinders 3 and 7, respectively. An end of an output lever 38 is engaged with a rod 15 for interconnecting the pair of right and left stepped pistons 14 and 16. A return spring 39 is stored in the end of the large diameter cylinder 7, and a sub piston 12 having a rod for moving by pressure the stepped piston 14 against a force of the return spring 39 is engaged with a sub cylinder 2 connected to the large diameter cylinder 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-position actuator for obtaining, for example, a select operation of an automatic gear transmission of a vehicle.

[0002]

2. Description of the Related Art Conventionally, as this kind of four-position actuator, there is one disclosed in Japanese Patent Application Laid-Open No. 10-141499. The four position actuator uses air pressure to constantly bias the piston to the right.

As shown in FIGS. 5 to 8, a description will be given of a four-position actuator as described above in which a spring is used to constantly bias the piston to the right. Cylinder 41, cylinder 42 with a larger diameter than cylinder 41, cylinder 43 with a larger diameter than cylinder 42, cylinder 44 with a slightly smaller diameter than cylinder 43, cylinder 45 with a slightly larger diameter than cylinder 41, and cylinder 44 A cylinder 46 having a slightly smaller diameter than the above is configured. On the other hand, the movable body 50 has a piston 51 fitted to the cylinder 41 and a piston 5 fitted to the cylinder 42.
2, a shaft portion 53, a piston 54 fitted to the cylinder 45,
Each of the pistons 55 has a larger diameter than the cylinder 45. A piston 62 is fitted on the shaft 53, and a piston 61 fitted on the cylinder 43 and having a flange on the left end is fitted on the piston 62. A piston 63 fitted to the cylinder 46 and having a flange at the right end is externally fitted to the piston 55. An end of an output lever 73 is engaged with a recess 74 of the movable body 50, and the output lever 73 can swing right and left around a support shaft 72. Cylinder 41
A return spring 71 is housed in the leftmost atmosphere chamber of the movable body 50.
Is constantly biased to the right.

In the first operating position shown in FIG. 5, an entrance 75 at the left end of the cylinder 43 is opened to the atmosphere,
When the pressurized air is supplied to the cylinder 46 from the entrance 76 at the right end of the cylinder 6, the piston 55 hits the left end wall of the cylinder 46, and the output lever 73 is tilted to the left most. now,
When pressurized air is supplied to the entrances 75 and 76, the piston 63 hits the left end wall of the cylinder 46, and the piston 61 and its flange move rightward until it hits the right end wall of the cylinder 43. To the right, and the piston 55 comes to the second operating position where it hits the flange of the piston 63 (FIG. 6).

Next, pressurized air is supplied to the entrance 75,
When the entrance 76 is opened to the atmosphere, the piston 63 is opened, and the movable body 50 is pushed by the piston 62, so that the piston 62 comes to the third operating position where it hits the right end wall of the cylinder 44 (FIG. 7). Next, when each of the entrances 75 and 76 is opened to the atmosphere, the movable body 50 is pushed rightward by the force of the return spring 71, and the piston 55 pushes the piston 63 against the right end wall of the cylinder 46 to be in the fourth operating position. (FIG. 8). As described above, the movable body 50 can be provided by supplying pressurized air to one or both of the entrances 75 and 76 or by opening one or both of the entrances 75 and 76 to the atmosphere.
Can be driven to the required four operating positions.

In the above-described conventional four-position actuator, the return spring 71 is used to bias the piston 51, so that the number of the inlet / outlet of the pressurized air and the number of electromagnetic switching valves are reduced to three.
Although the number was reduced from two to two, there were problems such as the complicated structure of the piston and the cylinder, the difficulty in designing the piston for obtaining pressure equilibrium, and the increase in the piston diameter.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a four-position actuator which can reduce the diameters of a piston and a cylinder and has a simple structure.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the structure of the present invention comprises first and second cylinders at both ends of a cylinder body.
The large-diameter cylinder is provided with a small-diameter cylinder inside each large-diameter cylinder, and a large-diameter portion of a pair of left and right stepped pistons is inserted into the small-diameter cylinder, and an annular piston fitted to the large-diameter cylinder is provided. The end of the output lever is engaged with the rod connecting the pair of left and right stepped pistons, and the return spring is housed at the end of the second large diameter cylinder. A sub-piston having a rod for pushing a stepped piston against the force of the return spring is fitted to a sub-cylinder connected to the first large-diameter cylinder.

[0009]

In the present invention, a pair of left and right stepped pistons is fitted to both ends of a cylinder body, a return spring is interposed at one end of the cylinder body, and a stepped piston is provided at the other end of the cylinder body. A sub-actuator for driving the piston is provided, and the output lever is engaged with a rod connecting the pair of left and right stepped pistons. A first port is provided between the sub-actuator chamber and the other end of the cylinder body, a second port is provided at the other end chamber of the sub-actuator, and a third port is provided at one end chamber of the cylinder body. A first solenoid on-off valve is provided on a pipe connecting a fluid pressure source (a pressurized air source, a hydraulic pressure source, etc.) to the first port,
Second solenoid on-off valves are respectively provided in pipes connecting the fluid pressure source and the second and third ports. The first to fourth operating positions are set in the rod by four combinations of the operation of energizing one or both of the first and second electromagnetic on-off valves and demagnetizing one or both of the first and second electromagnetic on-off valves. give.

[0010]

As shown in FIG. 1, a four-position actuator according to the present invention is provided with a sub-cylinder 2 and cylinders 3 to 7 on a main body 10 in order from the left end to the right. Smaller than the inner diameter of the cylinder 4
Is larger than the inner diameter of the small-diameter cylinder 6. The cylinder 5 is for inserting and supporting the rod 15.
An end of an output lever 38 supported on the main body 10 by a support shaft 37 is engaged with the notch 36, and the output lever 38 is driven to four operating positions by the left and right operations of the rod 15. The sub-cylinder 2 is fitted with a sub-piston 12 having a rod projecting rightward, and when pushed rightward from the position shown in the drawing, the sub-piston 12 hits the stop ring 35 and simultaneously returns the stepped piston 14 and the rod 15 to the return spring 39. It pushes to the right against the power of An annular piston 13 is fitted to the large-diameter cylinder 3, and the stepped piston 1 is
4 is fitted at the left end small diameter portion. The large diameter portion of the stepped piston 14 is smaller than the inside diameter of the small diameter cylinder 4. Accordingly, the right end of the large-diameter cylinder 3 is opened to the atmosphere via the cylinders 4 and 5. An annular piston 17 is fitted to the large-diameter cylinder 7, and a small-diameter portion of a stepped piston 16 formed at the right end of the rod 15 is fitted to the piston 17.
The large-diameter portion of the stepped piston 16 is slightly smaller than the inner diameter of the cylinder 6, so that the left end of the large-diameter cylinder 7 is opened to the atmosphere via the cylinder 6.

A return spring 39 is interposed between the stepped piston 16 and the right end wall of the main body 10. Specifically, the main body 10
A rod 34 projecting to the left from the right end wall of the stepped piston 16 can project to the right end cylindrical portion of the stepped piston 16, and is wound around the rod 34 between the inner end of the cylindrical portion and the right end wall of the main body 10. The mounted return spring 39 is interposed. An entrance 32 is provided in the left end chamber of the sub cylinder 2, and an entrance 31 is provided in the right end chamber. The right end chamber of the sub cylinder 2 is the large diameter cylinder 3 of the main body 10.
Connect to An entrance 33 is provided in the right end chamber of the large-diameter cylinder 7. Two electromagnetic switching valves 22 and 26 for supplying pressurized air to each of the entrances 31 to 33 or opening to the atmosphere are connected by pipes 24 and 28. The electromagnetic switching valve 22 has an electromagnetic coil 22a at a position where compressed air is supplied from a pressurized air source (not shown) to the tube 24 via the tube 21 and the inlet 23, and at a position where the tube 24 is connected to the exhaust pipe 25. It is configured to be switched by excitation and non-excitation of.

Similarly, the electromagnetic switching valve 26 is also
When “a” is excited, the position where the pressurized air in the tube 21 is supplied from the inlet 27 to the tube 28 is set. When the electromagnetic coil 26 a is demagnetized, the position is switched to a position where the tube 28 communicates with the exhaust pipe 29. The pipe 28 is connected to the entrance 32 and the entrance 33.

The inner diameter of the large-diameter cylinder 3 is larger than the inner diameter of the large-diameter cylinder 7, and the outer diameter of the small-diameter portion of the stepped piston 14 is larger than the outer diameter of the small-diameter portion of the stepped piston 16. The outer diameters of the small diameter portions of the stepped pistons 14 and 16 are set so that the force of the pressurized air pushing the stepped piston 14 rightward is greater than the force of the return spring 39 pushing the rod 15 leftward. Is done. The inner diameter of the sub-cylinder 2 may be any as long as the sub-piston 12 generates a force by air pressure that pushes the rod 15 rightward against the force of the return spring 39. In FIG. 1, the hatching of the main body 10 is omitted.

In the above embodiment, the cylinder 5 slidably guides the rod 15. The large diameter portion of the stepped piston 14 is provided for pushing the annular piston 13, and similarly, the large diameter portion of the stepped piston 16 only pushes the annular piston 17 to the main body 10. The stepped piston 14 may be integrally connected to the rod 15 after being assembled to the cylinder.

In the first operating position shown in FIG. 1, the electromagnetic switching valves 22, 26 are demagnetized, and the ports 31, 32, 33 are open to the atmosphere. At this time, the stepped piston 16 and the rod 15 are pushed leftward by the force of the return spring 39, the stepped piston 14 presses the piston 13 against the left end wall of the large-diameter cylinder 3, and the sub piston 12 is It is pressed against the left end wall. In the first operating position, the output lever 3
8 is in the position most rotated counterclockwise. Now, when the electromagnetic switching valve 26 is excited, pressurized air is supplied to the left end chamber of the sub-cylinder 2, and the stepped piston 12 hits the stop ring 35. At the same time, the large-diameter portion on the left side of the stepped piston 16 integral with the rod 15 via the stepped piston 14 hits the piston 17. However, the piston 17 receives air pressure in the right end chamber of the large diameter cylinder 7 and hits the left end wall of the large diameter cylinder 7.
At this time, the auxiliary piston 12 is connected to the stepped piston 16 and the rod 1.
Since the air pressure of the piston 17 and the stepped piston 16 and the force of the return spring 39 push the rod 15 to the left more than the air pressure pushing the 5 to the right, as shown in FIG. In addition, the rod 15 moves rightward by the stroke S1 until the large diameter portion of the stepped piston 16 hits the piston 17.

Next, when the electromagnetic switching valves 22 and 26 are excited, the piston 13 and the stepped piston 14 are pushed rightward by the force of the pressurized air supplied from the entrance 31 to the right end chamber of the cylinder 12, and the piston 13 is pushed. It hits the right end wall of the large diameter cylinder 3. At the same time, a stepped piston 16 integral with the rod 15
The piston 17 is pushed rightward by the large-diameter portion, and the piston 17 comes to the third operating position shown in FIG. At this time, rod 15 is
Has been moved rightward by the stroke S2 from the position shown in FIG. Next, the electromagnetic switching valve 22 is excited, and the electromagnetic switching valve 2 is turned on.
6, the right end chamber of the large-diameter cylinder 7 is opened to the atmosphere, and the pressurized air supplied to the left end chamber of the large-diameter cylinder 3 from the inlet / outlet 31 causes the stepped piston 14 and the stepped piston 16 integrated with the rod 15 to flow. Are pushed rightward, the stepped piston 14 hits the right end wall of the small diameter cylinder 4, and the piston 17 hits the right end wall of the large diameter cylinder 7. Accordingly, as shown in FIG. 4, in the fourth operating position, the rod 15 has moved rightward by the stroke S3 from the position shown in FIG.

As described above, the electromagnetic switching valves 22 and 26
One or both of them are excited, or the electromagnetic switching valves 22 and 26
The rod 15 can be driven to four operating positions by four combined operations of degaussing one or both of the two.

[0018]

As described above, according to the present invention, the first and second large-diameter cylinders are provided at both ends of the cylinder body, and the small-diameter cylinders are provided inside each of the large-diameter cylinders. A large diameter portion of the piston is inserted into the small diameter cylinder, and a small diameter portion of the stepped piston is fitted to an annular piston fitted to the large diameter cylinder, and a rod connecting the pair of left and right stepped pistons is formed. The end of the output lever is engaged, the return spring is housed at the end of the second large-diameter cylinder, and the sub-cylinder connected to the first large-diameter cylinder is stepped against the force of the return spring. Since the sub-piston having a rod for pushing the piston is fitted, the structure is simple, and the design and manufacture are easy.

[0019] The conventional one is troublesome in designing a piston for obtaining pressure equilibrium, and the piston diameter becomes large. On the other hand, according to the present invention, the piston diameter can be made smaller than the conventional one, so that space efficiency is reduced. high.

Since the number of electromagnetic switching valves is smaller than that of the conventional one, manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a first operating position of a four-position actuator according to the present invention.

FIG. 2 is a side sectional view showing a second operating position of the 4-position actuator.

FIG. 3 is a side sectional view showing a third operating position of the 4-position actuator.

FIG. 4 is a side sectional view showing a fourth operating position of the 4-position actuator.

FIG. 5 is a side sectional view showing a first operating position of a conventional four-position actuator.

FIG. 6 is a side sectional view showing a second operating position of the actuator.

FIG. 7 is a side sectional view showing a third operating position of the actuator.

FIG. 8 is a side sectional view showing a fourth operating position of the actuator.

[Explanation of symbols]

2: Secondary cylinder 3: Large diameter cylinder 4: Small diameter cylinder 5: Cylinder 6: Small diameter cylinder 7: Large diameter cylinder 10: Main body 12: Secondary piston 13: Piston 1
4: Stepped piston 15: Rod 16: Stepped piston 17: Piston 21: Pipe 22: Solenoid switching valve 26: Solenoid switching valve 2
8: Pipe 29: Exhaust tube 31: Doorway 32: Doorway 33: Doorway 34: Rod 35: Stop ring 38: Output lever 39: Return spring

Claims (2)

[Claims] 1. A large-diameter cylinder is provided on both ends of a cylinder body, and a small-diameter cylinder is provided inside each large-diameter cylinder. Fitting the small-diameter portion of the stepped piston into an annular piston fitted into the large-diameter cylinder,
An auxiliary cylinder connected to the first large-diameter cylinder, the end of the output lever being engaged with a rod connecting the pair of left and right stepped pistons, and a return spring being housed at the end of the second large-diameter cylinder. And a sub-piston having a rod for pushing the stepped piston against the force of the return spring. 2. A first solenoid-operated directional control valve is connected to a pipe connecting a fluid pressure source and an end chamber of a second large-diameter cylinder accommodating the return spring.
2. The four-position actuator according to claim 1, wherein second solenoid-operated directional control valves are respectively connected to pipes connecting the fluid pressure source and a chamber connected to the first large-diameter cylinder of the sub cylinder. 3.