JPH0665604U - Cylinder device - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object of the present invention to provide a cylinder device that can easily change cushioning performance with respect to load fluctuation and can exhibit a stable cushioning function over a long period of time. [Structure] Cylinder 1 having at least two ports
And a piston rod 7 movably arranged in the cylinder 1, a piston 9 integrally or separately provided on the piston rod 7, and formed at least on one end side of the piston 9 toward the end. And a sealing member 21 that is provided on the outer periphery of the piston 9 and seals with the cylinder 1. The position between the tapered portion 15 and the sealing member 21 and the piston 9 are provided. A flow passage 25 is formed between the one end and an end portion, and a check valve means 29 is provided in the flow passage 25 that allows only the flow toward the one end of the piston 9.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cylinder device, and more particularly, to an improved cushion mechanism.

[0002]

[Prior art]

 As a conventional cylinder device, for example, there is one shown in FIGS. This is shown in U.S. Pat. No. 3,626,812. First, there is a cylinder 101, and a piston rod 103 is accommodated in the cylinder 101 so as to be movable in the left and right directions in the figure. A piston 105 is formed on the piston rod 103. The piston 105 is formed with annular grooves 107, 109, 111, 113 at four locations in the axial direction, and rings 115, 117, 119, 121 are mounted in these annular grooves 107, 109, 111, 113. Has been done.

As shown in FIG. 7, a slit 123 is formed at the left end of the piston 105 in the figure. A slit 125 is formed on the right side of the annular groove 107 in the figure, and a slit 127 is also formed on the left side of the annular groove 113 in the figure. Further, the ring 115, as shown in FIG. 6, is provided with an abutment 129 (a portion where the end portions face each other with a gap therebetween).

In the above configuration, when pressure acts on the right side of the piston 105 in the drawing by the supply of hydraulic oil from a port (not shown), the piston 105 and the piston rod 103 move to the left side in the drawing. At that time, the hydraulic oil in the oil chamber A on the left side of the piston 105 in the figure flows out through the port C. Then, after the piston 105 moves and the ring 115 has passed the position of the port C, the outflow of the hydraulic oil via the port C is restricted. That is, the state is allowed only through the gap 129 of the ring 115. A desired cushioning function is exhibited by the resistance generated thereby.

On the other hand, when the hydraulic oil is supplied from the port C from the above state, the ring 115 is pressed against the left side surface of the annular groove 107 in the figure by the pressure as shown in FIG. To be As a result, as shown in the figure, the flow passage is secured, and the hydraulic oil is supplied into the oil chamber A through the slit 125, the annular groove 107, and the slit 123. Therefore, pressure acts on the left side of the piston 105 in the figure, and the piston 105 and the piston rod 103 move to the right side of the figure.

[0006]

[Problems to be solved by the device]

 The above-mentioned conventional configuration has the following problems. First, the cushion characteristic, especially the cushion characteristic at the initial stage of the throttling, is uniquely determined by the size of the port C, and there is a problem in that it cannot easily cope with load fluctuations. Further, the cushioning function is exerted by the ring 115 being in close contact with the right side surface of the annular groove 107 in the drawing, and allowing the hydraulic fluid to flow only through the mating port 129. At this time, it is necessary to seal the entire circumference of the ring 115, and if the ring 115 is deformed, the sealing performance may be impaired and the cushioning function may be impaired. Further, when the cushion function is exerted, the piston 105 must be provided with a slit 123 in order to secure a return flow path, and the ring 123 is easily deformed by the slit 123. . Further, the ring 115 may be deformed due to wear due to long-term use, the gap between the abutments 129 may be changed, and the cushion function may be impaired.

The present invention has been made on the basis of such a point, and an object of the present invention is to make it possible to easily change the cushioning performance with respect to load fluctuations and to exert a stable cushioning function for a long period of time. To provide.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, a cylinder device according to the present invention comprises a cylinder having at least two ports, a piston rod movably arranged in the cylinder, and a piston rod integrally or separately. A piston, a tapered portion formed on at least one end side of the piston and having a diameter gradually reduced toward the end, a seal member provided on the outer circumference of the piston for sealing between the piston and the cylinder, A flow passage formed between a position between the taper portion and the seal member and an end portion on one end side of the piston, and a check valve means provided in the flow passage and allowing only the flow toward the one end side of the piston. And is provided.

[0009]

[Action]

 First, when hydraulic oil is supplied from one port of the cylinder, its pressure acts on the other end of the piston, and the piston and piston rod move to one end of the piston. At that time, the hydraulic oil contained in one end of the piston flows out through the other port. Then, when the piston begins to pass through the other port, the hydraulic oil can flow out only through the tapered portion, and the throttling effect causes the cushioning function to be exerted. Conversely, when hydraulic oil is supplied from the other port, the check valve in the flow path is opened, so that hydraulic oil is supplied to the one end side of the piston through the flow path. As a result, the piston and piston rod move in the opposite direction. In this operation, when the load fluctuation is dealt with, the size of the tapered portion of the piston is appropriately changed.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. First, there is a cylinder 1, and ports 3 and 5 are formed in this cylinder 1. A piston rod 7 is accommodated in the cylinder 1 so as to be movable in the left-right direction in the figure, and a piston 9 is fixed to the piston rod 7 by a nut 11. An end plug 13 is attached to the left end of the cylinder 1 in the figure.

As shown in the figure, both ends of the piston 9 are gradually reduced in diameter, and taper portions 15 and 17 are formed. An annular groove 19 is formed substantially in the center of the piston 9 in the axial direction, and a seal member 21 is mounted in the annular groove 19. A groove 23 is formed at a position between the tapered portion 15 and the seal member 21, and the groove 23 is communicated with the port 27 via the flow path 25. A check valve 29 is mounted in the port 27, and is configured to allow only the flow of hydraulic oil from the groove 23 to the port 27. Similarly, a groove 31 is also formed at a position between the tapered portion 17 and the seal member 21, and the groove 31 is communicated with the port 35 via the flow path 33. A check valve 37 is installed in the port 35, and is configured to allow only the flow of hydraulic oil from the groove 31 toward the port 35.

The operation will be described based on the above configuration. First, it is assumed that hydraulic oil is supplied to the oil chamber B on the right side of the piston 9 in the figure through the port 3 and the pressure thereof is applied to the right side of the piston 9 in the figure. In that case, since the port 35 is closed by the check valve 37, the pressure acts on the right side of the piston 9 in the figure. Therefore, the piston 9 and the piston rod 7 move to the left side in the figure. At that time, the hydraulic oil in the oil chamber A on the left side of the piston 9 in the figure flows out through the port 5.

Then, the state eventually becomes as shown in FIG. That is, the left end of the piston 9 in the drawing passes through the port 5, and the hydraulic oil in the oil chamber A flows out to the port 5 side via the tapered portion 15. At this point, the outflow of hydraulic oil from the oil chamber A is gradually throttled, so that the cushion function starts to be exerted. Then, as shown in FIG. 3, a small amount of hydraulic oil flows out to the port 5 side through the tapered portion 15, and the throttling effect is maximized so that a desired cushioning function is exerted. At that time, since the port 27 is closed by the check valve 29, the hydraulic oil does not flow out there. The movement of the piston 9 is stopped by the end plug 13.

Next, in the above state, it is assumed that hydraulic oil is supplied from the port 5. By the supply of the hydraulic oil, the check valve 29 is separated from the port 27 and the port 27 is opened, as shown in FIG. Therefore, the hydraulic oil flows into the oil chamber A through the groove 23, the flow path 25, and the port 27, and also slightly into the oil chamber A. Therefore, pressure acts on the left side of the piston 9 in the figure, and the piston 9 and the piston rod 7 start moving rightward in the figure.

Although the above description is about the case where the cushion effect is exerted on the oil chamber A side, it is natural that the cushion effect can be exerted on the oil chamber B side in the same manner. .

As described above, according to this embodiment, the following effects can be obtained. First, it can easily cope with load fluctuations. That is, by appropriately changing the size (for example, the taper angle) of the tapered portion 15 of the piston 9, the initial cushion characteristic can be easily adjusted even if the size of the port 3 is the same. It is from. In particular, since the piston 9 can be attached to and detached from the piston rod 7, if a plurality of pistons 9 having different sizes of the tapered portion 15 are prepared in advance, the pistons 9 may be appropriately selected and attached.

Also, unlike the conventional ring, the cushioning performance does not change into a mischief due to its wear and deformation, so that stable cushioning performance can be provided for a long period of time. Further, in the past, a special ring machined with high accuracy was required, but in the case of this embodiment, it is sufficient to use the seal member 21 and the check valve 29 which are generally used, so that the cost is reduced. It

The present invention is not limited to the above-mentioned embodiment. The route and the like of the flow path 25 are not limited to those illustrated. Although the same cushion mechanism is provided on both sides of the piston 9 in the above-described embodiment, the cushion mechanism may be provided on the side where the cushion function is desired to be exhibited.

[0019]

[Effect of device]

 As described above in detail, according to the cylinder device of the present invention, the action of the tapered portion of the piston exerts the throttling effect and hence the cushioning function.Therefore, by appropriately changing the size of the tapered portion, load It can easily respond to fluctuations. Also, unlike the conventional structure, it does not use a special ring that may cause deformation or the like due to long-term use, so the desired cushioning function can be provided stably over a long period of time, and cost reduction is possible. Can be achieved °

[Brief description of drawings]

FIG. 1 is a sectional view of a cylinder device showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a cylinder device showing an embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a cylinder device showing an embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of a cylinder device showing an embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of a conventional cylinder device.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is an enlarged cross-sectional view showing a portion VII of FIG.

[Explanation of symbols]

 1 cylinder 3 port 5 port 7 piston rod 9 piston 15 taper part 23 groove 25 flow path 27 port 29 check valve (check valve)

Claims (1)

[Scope of utility model registration request] 1. A cylinder having at least two ports, a piston rod movably arranged in the cylinder, a piston provided integrally with or separately from the piston rod, and at least one end of the piston. A tapered portion formed on the side and gradually reduced in diameter toward the end,
A seal member which is provided on the outer circumference of the piston and seals between the cylinder, a flow path formed between a position between the taper portion and the seal member and one end side end portion of the piston, and the flow path. And a check valve means which is provided in the passage and allows only the flow toward the one end side of the piston.