JPH059646B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a hydraulic cylinder, and particularly to a hydraulic cylinder used in a drive system of a simulator device that simulates the motion of various vehicles on land, sea, and air.

[Prior art and problems to be solved by the invention]

Conventionally, this type of hydraulic cylinder has a sealing member attached to each sliding part (specifically, between the outer circumference of the piston rod and the rod cover that supports it, and between the outer circumference of the piston and the cylinder tube that supports it), which reduces frictional resistance. Due to the large resistance, state clipping, especially at low speeds, has the disadvantage that the above-mentioned simulator system gives the occupant a feeling different from that of a real vehicle. In addition, this type of hydraulic cylinder is required to have quick and smooth operational response under any conditions of use, and it has been confirmed through experiments that this can be effectively achieved by reducing the frictional resistance of both sliding parts mentioned above. .

[Means to solve the problem]

The present invention has been made to solve the above-mentioned problems, and includes a plurality of bearing pockets that are provided on the outer periphery of a piston rod at equal intervals in the circumferential direction and extend a predetermined length in the axial direction to form bearing pockets to which pressure oil is supplied. a first linear groove, a plurality of second linear grooves each provided in each land formed between the first linear grooves and extending in the axial direction by a set amount beyond the first linear groove; a pair of annular grooves that are provided at both ends of the linear groove and communicate the respective ends of the second linear groove, a fuel filler port that communicates with each of the first linear grooves, and each of the second linear grooves. A hydrostatic bearing for holding the piston rod is provided integrally with the rod cover, and includes a linear groove and an oil drain port that communicates with each of the annular grooves and is connected to the tank. between the annular groove and the rod-side oil chamber, and between the other annular groove that communicates with the oil drain port and the oil reservoir equipped with a discharge port connected to the tank,
A plurality of annular grooves are provided to form a labyrinth with the outer periphery of the piston rod without providing a sealing member for preventing oil leakage around the outer periphery of the piston rod, and the grooves are integrally assembled to one end of the piston rod and installed inside the cylinder tube. A discharge port is provided on the axially intermediate outer periphery of the piston that divides the piston into a head side oil chamber and a rod side oil chamber, and is connected to a tank at a portion of the piston rod that is always exposed to the outside. An annular groove communicating through the communication hole is provided, and a seal member is provided between the annular groove and the head side oil chamber and between the annular groove and the rod side oil chamber to prevent oil leakage from the outer periphery of the piston. The present invention is characterized in that a plurality of annular grooves are provided, each forming a labyrinth with the inner periphery of the cylinder tube.

[Operations and Effects of the Invention] In the hydraulic cylinder according to the present invention, an oil film is only formed between the outer periphery of the piston rod and the rod cover which is its supporting part by the hydrostatic bearing and the labyrinth, and no sealing member is provided. Since the piston rod is always held in a floating state at an equilibrium position by the static pressure bearing, even if the piston rod moves in its axial direction under an external force (load), the frictional resistance between the piston rod outer periphery and the rod cover is reduced. is kept at a very small value. Since only an oil film is formed by the labyrinth between the outer periphery of the piston and the cylinder tube which is the supporting portion of the piston, and no sealing member is provided, the frictional resistance between the outer periphery of the piston and the cylinder tube is maintained at an extremely small value. Hydraulic oil that inevitably leaks in the axial direction along the outer periphery of the piston when the hydraulic cylinder is operated is stored in an annular groove provided on the axially intermediate outer periphery of the piston, and transferred between a communication hole provided in the piston and the piston rod and the piston rod. Since the hydraulic oil flows into the tank through the provided discharge port, when pressure oil is being supplied to the oil chamber on the head side or rod side, the hydraulic oil will not flow into the oil chamber on the rod side or head. The hydraulic pressure is not increased, and the operating performance of the hydraulic cylinder is maintained well. These effects are achieved comprehensively, ensuring quick and smooth operational response, and when this hydraulic cylinder is used in the drive system of a simulator device, it provides the occupants with a feeling that is extremely similar to that of an actual vehicle. can give.

【Example】

An embodiment of the present invention will be described below based on the drawings. FIG. 1 shows a hydraulic cylinder 100 according to the present invention, in which:
A head cover 12 is attached to the left end of the cylinder tube 10.
is fixed, and a rod cover 14 is fixed to the right end of the piston rod 16, and a cushion ring 18 and piston 2 are integrally assembled to the left end of the piston rod 16.
0 is assembled so as to be slidable in the axial direction. The head cover 12 has a port 12a connected to a known switching valve 22, and this port 12a communicates with the left chamber (height side oil chamber) R1 divided by the piston 20 via the cushion mechanism A. ing. The cushion mechanism A cushions the movement of the left end of the piston rod 16, the piston 20, etc., and includes small holes 10a formed in the cylinder tube 10 and sequentially opened and closed by the piston 20, and a port attached to the head cover 12. 12a
Restriction 24 and port 1 that restrict the communication between the left ventricle R1 and the left ventricle R1
2a to the left ventricle R1. Rod cover 1
4 has a port 14a connected to the switching valve 22, and this port 14a communicates with the right chamber (rod side oil chamber) R2 partitioned by the piston 20. In this embodiment, as shown in the partially enlarged views of FIGS. 2 and 3, a hydrostatic bearing B is integrally cut into the rod cover 14. The hydrostatic bearing B includes a rod cover 14, a guide bush 28 and a bearing sleeve 30 assembled to the rod cover 14,
It is constituted by a chain yoke 32 screwed onto this bearing sleeve 30. The guide bush 28 is
It has three annular grooves 28a on the inner periphery that form a labyrinth with the outer periphery of the piston rod 16, an annular recess (groove) 28b on the right end, an annular groove 14b provided in the rod cover 14, and an oil drain port 14.
It has a groove 28c extending in the radial direction and communicating with the tank 28c (connected to a tank, not shown). The bearing sleeve 30 is positioned on the rod cover 14 by a pin 34, and has three annular grooves 30a forming a labyrinth with the outer circumference of the piston rod 16 on the inner periphery of the right end, as well as a pair of large and small annular grooves 30b and 30c. The annular groove 30b connects to the annular groove 14d provided in the rod cover 14 and the oil drain port 1 through the obliquely bored communication hole 30d and the groove 30e provided along the outer periphery in the axial direction.
4e (connected to a tank not shown). Also, a sponge 3 is provided in the annular groove 30c.
6 is fitted to reduce sliding resistance and prevent dust from entering. For this reason, sponge 36
Although there is a concern that oil may leak through the rod cover 14, in this embodiment, a holding plate 37 having an annular oil reservoir 37a is fixed to the rod cover 14.
Further, the hydraulic oil contained in the oil reservoir 37a is discharged from a discharge port 37b provided below to a tank (not shown). Note that it is also possible to implement without the sponge 36. On the other hand, on the left inner periphery of the bearing sleeve 30, there are five wide linear grooves 30f in the circumferential direction that extend a predetermined length in the axial direction and form bearing pockets P to which pressure oil is supplied to the outer periphery of the piston rod 16. Each land provided at equal intervals and formed between the linear grooves 30f extends in the axial direction by a set amount beyond the linear groove 30f, and has an annular recess 28b of the guide bush 28 and a bearing sleeve 30 at both ends. An annular groove (substantially an annular recess 28b) formed by the left end surface of
Five narrow linear grooves 30g are provided which communicate with the annular groove 30b. In this embodiment, a groove 30e provided on the outer periphery of the intermediate portion of the bearing sleeve 30 and a groove 30h provided on the outer periphery of the left end portion are provided correspondingly to each of the linear grooves 30g, and the grooves 30e and 30h are provided in correspondence with each linear groove 30g. It communicates with the linear groove 30g. Each tooth yoke 32 is removably screwed from the outside into a stepped hole 30j provided in the intermediate portion of the bearing sleeve 30 in the radial direction corresponding to each linear groove 30f. The end communicates with each linear groove 30f, and the outer end communicates with the bearing sleeve 3
It communicates with a fuel filler port 14g provided on the rod cover 14 through an annular groove 30k provided on the outer periphery of the rod cover 14 and an annular groove 14f provided on the inner periphery of the rod cover 14. In addition, in this embodiment, the insertion holes 14 corresponding to each of the cheese yokes 32 are inserted through which each cheese yoke 32 can be inserted.
h is provided in the rod cover 14 coaxially with the stepped hole 30j, and is closed by a plug 38. With this configuration, in this embodiment, each of the chain yokes 32 can be easily replaced from the outside, and the pressure in each linear groove 30f is transferred to the radial hole 30l provided in the bearing sleeve 30 and the port 14i provided in the rod cover 14. In addition to reading through the sensor, the hydrostatic bearing B can be easily adjusted. In the hydrostatic bearing B configured in this way, each linear groove 30f is connected to each linear groove 30g, and the annular recess 2
8b and each other linear groove 3 by an annular groove 30b.
0f and the right ventricle R2, and the oil pressure in each linear groove 30f does not fluctuate due to the influence of the oil pressure in the other linear grooves 30f and the right ventricle R2, so no external force is applied to the piston rod 16. When the (load) acts in the radial direction and shifts to one side, the hydraulic pressure on that side increases and the hydraulic pressure on the opposite side decreases, and the force to push it back to its original position is accurately obtained, and the piston rod 16 is in a floating state at an equilibrium position. It is maintained at In this embodiment, as shown in FIGS. 1 and 4, ten annular grooves 20a are provided along the entire length of the piston 20 to form a labyrinth with the cylinder tube 10, and these annular grooves 20a An annular groove 20b is provided in the middle of the piston 20, and a wide annular groove 20c is provided on the inner periphery of the piston 20 in correspondence with the annular groove 20b. 20d. On the other hand, the shaft center of the piston rod 16 has plugs 40 at both ends.
A discharge hole 16a is provided which is closed by a drain hole 16a. The left end of this discharge hole 16a passes through the annular groove 2 of the piston 20 through the communication hole 16b provided in the radial direction.
The piston rod 16 is connected to a discharge port 16c provided in a portion of the piston rod 16 that is always exposed to the outside at the right end. This discharge port 16c
is connected to a tank (not shown) by a vinyl hose (not shown). With this configuration, in this embodiment, both chambers R
1 and R2, and then drain the hydraulic fluid that inevitably leaks in the axial direction along the outer peripheral surface of the piston 20 to the annular groove 20b, the communication hole 20d, the annular groove 20c, and the annular groove 20c of the piston 20. The communication hole 16b of the piston rod 16, the discharge hole 16a,
It can be led to the tank through the discharge port 16c, and both chambers R1 and R2 can be separated without using a piston ring as a sealing member. In summary, in this embodiment, an oil film is formed between the outer periphery of the piston rod 16 and the rod cover 14, which is its supporting part, by the hydrostatic bearing B and the labyrinth, and no sealing member is provided. Since the piston rod 16 is always held in a floating state at an equilibrium position by B, even if the piston rod 16 moves in its axial direction when an external force (load) is applied to the piston rod 16, the distance between the outer periphery of the piston rod 16 and the rod cover 14 remains constant. The frictional resistance is maintained at an extremely low value. Since only an oil film is formed by a labyrinth between the outer periphery of the piston 20 and the cylinder tube 10 that is its supporting part, and no sealing member is provided, the frictional resistance between the outer periphery of the piston 20 and the cylinder tube 10 is maintained at an extremely small value. be done. An annular groove 2 provided on the axially intermediate outer circumference of the piston 20 to prevent hydraulic oil that inevitably leaks in the axial direction along the outer circumference of the piston 20 when the hydraulic cylinder is operated.
0b and communicating holes 20d and 16 provided in the piston 20 and the piston rod 16.
b, 16a and the discharge port 16c provided on the piston rod 16, so that when pressure oil is being supplied to the oil chamber R1 or R2 on the head side or the rod side, the oil chamber R2 or the oil chamber on the rod side or the head side Since hydraulic oil does not flow into R1, the oil pressure in the oil chamber R2 or R1 is not increased, and the operating performance of the hydraulic cylinder is maintained satisfactorily. These effects are achieved comprehensively, ensuring quick and smooth operational response, and when this hydraulic cylinder is used in the drive system of a simulator device, it provides the occupants with a feeling that is extremely similar to that of an actual vehicle. can give.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of a hydraulic cylinder according to the present invention, Fig. 2 is an enlarged view of the same essential parts, Fig. 3 is a sectional view taken along the line of Fig. 2, and Fig. 4 is a piston shown in Fig. 1. FIG. Explanation of symbols, 10... Cylinder tube, 14
... Rod cover, 14g ... Fuel filler port, 14c,
14e...Oil drain port, 16...Piston rod, 1
6c...Discharge port, 20...Piston, 20a
...An annular groove forming a labyrinth, 20b...An annular groove communicating with the discharge hole, 28a, 30a...An annular groove forming a labyrinth, 28b, 30b...An annular groove communicating the second linear groove, 30f... …First
Linear groove, 30g...Second linear groove, 37a...
Oil sump, 37b...Discharge port, B...Static pressure bearing,
P...Bearing pocket, R1...Head side oil chamber, R
2... Rod side oil chamber, 100... Hydraulic cylinder.

Claims (1)

[Claims] 1 A plurality of first linear grooves are provided on the outer periphery of the piston rod at equal intervals in the circumferential direction and extend a predetermined length in the axial direction to form bearing pockets to which pressure oil is supplied; a plurality of second linear grooves provided in each land to be formed and extending in the axial direction by a set amount beyond the first linear groove; and a plurality of second linear grooves provided at both ends of these second linear grooves, respectively. a pair of annular grooves that connect the respective ends of the grooves, a fuel filler port that communicates with each of the first linear grooves, and a tank that communicates with each of the second linear grooves and each of the annular grooves; A hydrostatic bearing for holding the piston rod is integrally provided in the rod cover, and a hydrostatic bearing is provided between one annular groove communicating with the oil drain port and the rod side oil chamber and between the oil drain port. A labyrinth is formed by the outer periphery of the piston rod without providing a sealing member for preventing oil leakage from the outer periphery of the piston rod between the other communicating annular groove and the oil reservoir provided with the discharge port connected to the tank. An annular groove is provided on the axially intermediate outer periphery of the piston, which is integrally assembled to one end of the piston rod and divides the inside of the cylinder tube into a head side oil chamber and a rod side oil chamber. An annular groove is provided that communicates with the exhaust port provided in the part exposed to the outside and connected to the tank through the communication hole provided in the piston and the piston rod, and between this annular groove and the oil chamber on the head side, and between the annular groove and the rod side. A hydraulic cylinder, characterized in that a plurality of annular grooves are provided between the oil chambers, each forming a labyrinth with the inner circumference of the cylinder tube without providing a seal member for preventing oil leakage around the outer circumference of the piston.