JPH0577882B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a cylinder device having a speed control mechanism, and more specifically, when performing a predetermined operation using a fluid pressure cylinder, the piston in the cylinder is controlled to a predetermined position. The present invention relates to a cylinder device having a speed control mechanism configured to stop a piston at a fixed position at the end of a stroke without impact even when the piston is rapidly moved to a certain position.

[Prior Art] Generally, when an object is transferred in conjunction with the piston of a fluid pressure cylinder, when the piston is moved to the end of its stroke at normal speed, a very large impact is generated on the object due to inertia, etc. This may damage the object or the hydraulic cylinder and generate noise. Therefore, it is necessary to reduce the impact of the transferred object at the end of its stroke by reducing the moving speed of the piston near the end of its stroke.

For this reason, a speed control device as exemplified in FIG. 1 has conventionally been used. That is, in this speed control device, a passage 12 extends from a switching valve 4 connected to a pressure source 2, and the tip thereof communicates with one chamber 10 in a cylinder 8 partitioned by a piston 6. On the other hand, the other chamber 1 in the cylinder 8
A passage 18 is extended from 4 and connected to the flow control valve 1.
Connected to 6. In this case, a passage 20 from the flow control valve 16 to the switching valve 4 is provided, and
The flow control valve 16 has a passage 26 that is opened and closed by a main valve 24 attached to a diaphragm 22.
is formed. A coil spring 30 is installed inside the chamber 25 partitioned by the diaphragm 22.
is provided, and the diaphragm 22 is pressed under the action of this coil spring 30. Also, aisle 2
6 is provided with a valve 33 that is constantly pressed upward by a coil spring 31.
A truncated conical valve 3 is placed in the space defined in the center of 3.
The tip end of 8 faces to define a side passage 34. on the other hand,
A passage 40 branches off from the passage 12 on the way, and a speed controller 46 consisting of a variable throttle valve 42 and a check valve 44 is installed at one end of the passage 40.
has been set up. Further, a passage 48 communicating from the speed controller 46 to the chamber 28 is connected.

The operation of such a conventional speed control device is as follows.

First, fluid supplied from the pressure source 2 passes through the switching valve 4 and the passage 12 and is pressurized into the chamber 10, thereby causing the piston 6 to move in the direction of the arrow. As a result, the fluid in the chamber 14 is sequentially sent out of the apparatus through the passage 18, the flow rate control valve 16, the passage 20, and the switching valve 4. At this time, the pressure inside the passage 12 is
Since the fluid is introduced into the chamber 28 defined by the diaphragm 22 through the variable throttle valve 42 and the passage 48, the fluid pressure in the chamber 28 gradually increases. When the fluid pressure exceeds the set pressure, the diaphragm 22 is displaced and the main valve 24 is lowered in the figure to close the passage 26. Therefore, after that, the piston 6 moves in accordance with the flow rate of the fluid passing through the side passage 34 constricted by the valves 33 and 38, and its movement speed becomes low.

[Problems to be Solved by the Invention] In such a speed control device, the deceleration start position of the piston 6 is determined by the degree of increase in the fluid pressure in the chamber 28. That is, when performing a plurality of displacement strokes of the piston 6, the degree of pressure increase must be the same each time in order to always decelerate the piston 6 from a predetermined position. However, the degree of this pressure increase depends on changes in the temperature of the fluid, changes in the frictional force applied to the piston 6, changes in load due to changes in the transferred object (not shown) connected to the piston rod, and the accuracy of the variable throttle valve 42. is significantly influenced by a variety of factors. Therefore, in reality, the piston 6 cannot always be decelerated from a predetermined position, resulting in the inconvenience that the object to be transported cannot be suitably moved.

In addition, there are speed control devices that use a mechanically operated valve operated by a cam using the mechanical movement of a piston, and speed control devices that control electrically using reed switches, limit switches, etc. There are many elements and the manufacturing process is complicated, so all conventional devices have high manufacturing costs, and devices that are electrically controlled have disadvantages such as the need to install a dedicated electric circuit. It existed.

The present invention has been made in order to overcome the above-mentioned disadvantages, and an object of the present invention is to provide a cylinder device having a speed control mechanism that ensures stroke reproducibility and prevents excessive impact at the end of the stroke. shall be.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a piston 76 that is slidably installed inside the piston 76 and has a first port 91 and a second port 60 near the ends thereof. established,
and a cylinder 52 with a plurality of holes 62a and 62b defined between the first port 91 and the second port 60; a speed control mechanism 88 provided at one end of the cylinder 52; switching means for selectively communicating the plurality of holes 62a, 62b defined in the cylinder 52 with a passage 114 provided in the speed control mechanism 88; A sliding member 106 is displaced by pressure fluid introduced from the holes 62a and 62b through the switching means, and the first port 91 and the chamber 78 on the piston head side are moved by the displacement operation of the sliding member 106.
a main valve 100 that opens and closes a passage 92 communicating with the
a throttle valve 96 facing a side passage 94 communicating the piston head side chamber 78 and the first port 91;
It is characterized by having the following.

[Operation] A hole formed in the middle of the cylinder and a speed control mechanism provided at one end of the cylinder are communicated via a conduit. Therefore, when the piston passes through the hole, the pressure that operates the piston is directly transmitted to the speed control mechanism via the conduit, and the main valve is closed. As a result, the chamber on the piston head side of the cylinder becomes a cushion chamber. Therefore, the piston is always located at a certain point in the cylinder, i.e.
Braking is applied from a position downstream of the hole. in the end,
The piston is braked from a fixed position regardless of changes in the temperature of the fluid, changes in the frictional force applied to the piston, and changes in the load connected to the piston rod.

[Embodiments] Next, preferred embodiments of a cylinder device having a speed control mechanism according to the present invention will be described in detail with reference to the accompanying drawings.

In the figure, reference numeral 50 indicates a cylinder device having a speed control mechanism, and a cylinder 52 forming a part thereof has one end open and the other end closed. In this case, a fixing member 54 for mounting the cylinder device 50 on a base (not shown) is fixed to the closed side wall of the cylinder 52 together with a fixing member 90 (described later) via a bolt 53, and
A hole 58 is drilled in the side wall to accommodate the piston rod 80.
Insert airtightly through the O-ring. The longitudinally extending side wall of the cylinder 52 has a port 60 for introducing pressure fluid, and a hole 62a for leading out the pressure fluid under the action of displacement of the piston.
62b is drilled in advance. Further, a cylindrical member 64 is slidably fitted onto the cylinder 52. Seal members, that is, O-rings 66a to 66f, are fitted into the cylindrical member 64 at predetermined positions. A hole 68 is formed through the cylindrical member 64, and a screw hole 70 is formed in communication with the hole 68, into which a screw 72 is screwed. In addition, O-rings 66c and 66d
A substantially L-shaped passage 74 opening toward the cylinder 52 is bored between the cylinder 52 and the cylinder 52 .

A piston 76 is housed inside the cylinder 52 in a slidable and airtight manner by a seal member 79, and the chamber inside the cylinder 52 is divided into a chamber 77 and a chamber 78. At this time, the sealing member 79 fitted into the piston 76 has a cross-sectional diameter that is equal to that of the holes 62a, 62.
The hole 6 is selected to be larger than the diameter of b.
2a and 62b. Further, a piston rod 80 is fixed to the piston 76, and as described above, the piston rod 80 is slidably inserted into the hole 58 in an airtight manner. In this case, a threaded portion 82 is formed on the piston rod 80, and the threaded portion 82 is inserted into the piston 76 and the washer 84, and the nut 86 is screwed onto the piston 76.
6 and the piston rod 80 are integrated.

On the other hand, a speed control mechanism 88 is fitted to the other open end of the cylinder 52. In this case, an angled fixing member 90 is fixed to the body constituting the speed control mechanism 88, and the cylinder device 50 is positioned by this fixing member 90 and the fixing member 54. A port 91 is formed in speed control mechanism 88 and is in communication with passage 92 . A side passage 94 having a narrow diameter is provided in communication with the passage 92, and a variable throttle valve 96 is provided facing the side passage 94. The side passage 94 is essentially for bypassing the passage 92;
2 defines a chamber 95 in which a main valve 10, which will be described later, is installed.
0 is movably stored.

On the other hand, a hole 98 is formed above the chamber 95,
The columnar portion 102 of the main valve 100 is made to face this hole 98 . That is, the main valve 100 is always pressed upward by the coil spring 104 housed in the chamber 95, so that the tip of the columnar portion 102 faces the chamber 108 defined in the speed control mechanism 88. Enter. The chamber 108 is a disc-shaped sliding member 106 that slides.
is separated from a chamber 110 by a passageway 112 which communicates with the passageway 92 and thus with the chamber 78 of the cylinder. Also, a passage 11 that opens from the chamber 108 to the outside of the speed control mechanism 88
4, the passages 114 are arranged in parallel in the longitudinal direction of the cylinder 52, and the passages 7 of the cylindrical member 64 are arranged in parallel in the longitudinal direction of the cylinder 52.
4 and facing one end of the pipe line 128 connected to the pipe 128. The pipe line 128 is made of a pipe body that can be expanded and contracted in its longitudinal direction. Note that one end of the coil spring 118 is engaged with the sliding member 106, while
A receiving member 120 is engaged with the other end of this coil spring 118. In this case, the speed control mechanism 8
A hole 122 having an internal screw is bored in a part of 8, and a columnar part 124 formed integrally with the receiving member 120 is slidably inserted into the hole 122, and further, A screw 126 is inserted into the hole 122 so as to contact the columnar part 124. Therefore, by turning the screw 126, the coil spring 1
It is easily understood that the elastic force of 18 can be adjusted.

In addition, a rod 13 with threaded portions formed on both ends.
0 into the hole 68 of the cylindrical member 64, one of the threaded portions is screwed into the body of the speed control mechanism 88, the other threaded portion of the rod 130 is inserted into the plate 132, and a nut is inserted into the threaded portion. 134 to tighten this rod 130. In this case, the plate 132
is fixed to one side wall of the cylinder 52 with a bolt 135. Note that the cylindrical member 64 has a screw 72.
The hole 62 is positioned and fixed by tightening and loosening the rod 130 and communicates with the passage 74.
A or 62b can be arbitrarily selected. Therefore,
The cylindrical member 64, the passage 74 bored in the cylindrical member 64, and the conduit 128 communicating the passage 74 with the passage 114 of the speed control mechanism 88 constitute a switching means.

The cylinder device according to the present invention is basically constructed as described above, and the operation and effects of the device will be explained next.

First, when the piston 76 at the position shown in FIG. 2 performs a stroke to move rightward in the figure, fluid is forced into the chamber 77 from the port 60. This pressurized fluid pushes the piston 76 and
move in the direction of At that time, the pressure fluid in the chamber 78 flows through the hole 62a, the passage 74, the pipe line 128, and the passage 114.
is introduced into the chamber 108 through the passageway 112.
It is introduced into the chamber 110 through. So, Room 108
and 110 are equal, and main valve 100 remains open. Therefore, the fluid in chamber 78 is led out from port 91 through passage 92.

In this way, the piston 76 moves from its initial position in the direction A shown in the figure, and then the piston 76
passes through the opening of the hole 62a. At that moment, the relatively high pressure fluid in the chamber 77 introduced from the port 60 sequentially flows through the hole 62a, the passage 74, the conduit 128,
It is introduced into chamber 108 via passage 114. The pressure fluid introduced into this chamber 108 moves against the sliding member 106.
is pushed upward in the figure, and as a result, the columnar part 10
Regulations have been lifted for coil spring 1.
04 causes the main valve 100 to rise and close the passage 92 (see FIG. 3). By this,
Since the fluid sent out from the chamber 78 passes through the side passage 94 whose opening degree is restricted by the variable throttle valve 96, the amount of fluid sent out from the chamber 78 is reduced.
As a result, the moving speed of the piston 76 is reduced. In this case, the deceleration starts at the moment the piston 76 passes through the opening of the hole 62a, so the deceleration start position is always constant. That is, the piston 76
The piston 76 is reliably decelerated from a predetermined position without being affected by changes in the load applied to the piston or changes in the temperature of the fluid. Note that the degree of deceleration of the piston 76 can be freely set by adjusting the variable throttle valve 96.

In this way, the piston 76 can quickly move to a position where it passes through the opening of the hole 62a, be reliably decelerated from that position, and be stopped at a predetermined position.

Also, the cylindrical member 64 is moved to open the passage 74 into the hole 6.
2b, in the stroke in this case, the piston 76 starts decelerating from the position where it passes through the opening of the hole 62b. That is, the cylinder device 50 can arbitrarily change the deceleration start position during the stroke of the piston 76. Further, by configuring the cylinder 52 and the cylindrical member 64 with a large number of holes that perform the same function as the holes 62a and 62b for introducing fluid pressure into the chamber 108, the deceleration starting position of the piston 76 can be adjusted. It is also possible to further expand the selection range.

On the other hand, when the piston 76 is caused to perform a stroke moving from the position shown in FIG. 3 to the position shown in FIG.
After stopping the injection of fluid into chamber 77, port 91
Fluid is forced into the passage 92 from the inside. At this time, room 10
Since no pressure fluid is introduced into the sliding member 10
6 is displaced downward in the figure under the action of the coil spring 118, and the main valve 100 opens the passage 92. Therefore, the piston 76 is pressed by the fluid forced into the passage 92 and starts moving in the direction of arrow B. Further, even when the piston 76 passes through the opening of the hole 62a, the state of the main valve 100 does not change, so the piston 76 moves at a normal speed to the end of the predetermined stroke.

[Effects of the Invention] As explained above, in one stroke of the piston of the cylinder device according to the present invention, deceleration always starts reliably from a predetermined position, and in the other stroke, the piston smoothly moves at a normal speed. Move to. Therefore, when an object is moved back and forth, the use of this device provides the effect of reliably avoiding impact at the terminal end. Furthermore, since an arbitrary deceleration start position can be selected, it is possible to meet various requests. Moreover, this device has the advantage of being simpler in construction and cheaper than a speed control device using a mechanically operated valve, or a speed control device using a reed switch, a limit switch, or the like.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a speed control device according to the prior art. FIG. 2 is a schematic vertical cross-sectional view of the cylinder device having the speed control mechanism according to the present invention when the piston is located at one stroke end. 3 is a schematic longitudinal sectional view of the cylinder device shown in FIG. 2 when the piston is located at the other stroke end, and FIG. 4 is a schematic perspective view of the cylinder device shown in FIGS. 2 and 3. 50...Cylinder device, 52...Cylinder, 6
0... Port, 62a, 62b... Hole, 64...
Cylindrical member, 76...Piston, 80...Piston rod, 82...Threaded portion, 88...Speed control mechanism, 91...Port, 96...Variable throttle valve, 10
0...Main valve, 102...Column portion, 104...Coil spring, 106...Sliding member, 118...
Coil spring, 120... Reception member, 128
...Pipeline.

Claims (1)

[Scope of Claims] 1. A piston 76 is slidably installed inside the piston, and a first port 91 and a second port 60 are provided near the ends, respectively, and the first port 91 and the second port 6
0; a speed control mechanism 88 provided at one end of the cylinder 52; and a speed control mechanism 88 provided at one end of the cylinder 52; switching means for selectively communicating between the holes 62a, 62b and a passage 114 provided in the speed control mechanism 88; A sliding member 106 is displaced by pressure fluid introduced through a means, and the first port 91 and the chamber 78 on the piston head side are moved by the displacement operation of the sliding member 106.
a main valve 100 that opens and closes a passage 92 communicating with the
a throttle valve 96 facing a side passage 94 communicating the piston head side chamber 78 and the first port 91;
A cylinder device having a speed control mechanism.