JPH0531281Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cylinder device having a speed control mechanism, and more specifically, to a cylinder device having a speed control mechanism, and more specifically, when a fluid pressure cylinder is used to perform a predetermined operation, the piston in the cylinder is rapidly moved to a predetermined position. Even if it is,
The present invention relates to a cylinder device having a speed control mechanism configured to stop effectively and without impact at the end of a stroke.

Generally, when moving an object in conjunction with the piston of a fluid pressure cylinder, if the piston moves at normal speed to the end of its stroke, a very large impact will be applied to the object due to inertia, etc. Alternatively, the hydraulic cylinder may be damaged and may also 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 rate control valve 16 has a passage 26 that is opened and closed by a valve body 24 attached to a diaphragm 22.
is formed. A coil spring 30 is installed inside the chamber 28 partitioned by the diaphragm 22.
is provided, and the diaphragm 22 is pressed under the action of the spring 30. Further, a valve 33 that is constantly pressed upward by a coil spring 31 is provided in the passage 26, and a truncated conical valve 38 has a distal end portion in a space defined in the center of the valve 33. faces and defines a passageway 34. On the other hand, the passage 12 branches off into a passage 40 at one end thereof, and a speed controller 46 consisting of a variable throttle valve 42 and a check valve 44 is disposed at one end of the passage 40. Furthermore, the speed controller 4
A passage 48 communicating with the chamber 28 is connected from the chamber 6 .

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 to the outside of the apparatus via the passage 18, the flow 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 becomes equal to or higher than the set pressure, the diaphragm 22 is displaced and the valve body 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, so that its movement speed becomes low.

Therefore, in the 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, piston 6
When performing the displacement stroke a plurality of times, 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 fact, the piston 6 cannot always be decelerated from a predetermined position, and the object to be transported cannot be moved appropriately.

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 naturally have drawbacks such as the need to install a dedicated electric circuit. Was.

The present invention has been made to overcome the above-mentioned disadvantages, and is provided with a hole in the side wall of the fluid pressure cylinder that communicates with the space within the stroke range of the piston, and the fluid pressure derived from the hole is The speed control mechanism is configured to effectively utilize the change in pressure to throttle the fluid pushed out of the cylinder, ensuring stroke reproducibility that reliably decelerates the piston from a predetermined position, and prevents excessive impact at the end of the stroke. An object of the present invention is to provide a cylinder device having the following features.

In order to achieve the above object, the present invention provides a cylinder in which fluid is alternately supplied from first and second holes to both chambers partitioned by the piston of the fluid pressure cylinder to move the piston. A third hole is formed in the side wall of the cylinder, a flow control valve is connected to the second hole and the third hole, and the flow control valve connects the first port, the second port, and these ports. and a first and second chamber separated by a diaphragm, the second chamber communicating with a third hole and being displaced in accordance with the operation of the diaphragm. Provided integrally with the diaphragm that opens and closes the passage,
A first coil spring and a second coil spring are engaged with the diaphragm so that resilient forces are exerted in opposite directions, and the first port and the second port are communicated with each other and a throttle valve faces the diaphragm. By providing a side passage, the first and second chambers are held at the same pressure under the opening action of the valve body before the piston passes through the third hole, and after the piston passes through the third hole, the pressure in the first and second chambers is maintained at the same pressure. Supply pressure is introduced into the second chamber through the three holes, the diaphragm closes the valve body under the pressure difference between the first chamber and the second chamber, and the supply pressure is introduced into the first port through the side passage. It is characterized in that the cylinder chamber pressure on the second hole side is increased by causing the fluid in the second hole to escape while being throttled to the side, thereby applying a cushioning action to the piston.

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.

The cylinder device having the speed control mechanism of this embodiment includes a switching valve 50, speed controllers 52, 5
4. Consists of a flow rate control valve 56, a fluid pressure cylinder 58, and a plurality of passages. The switching valve 50
is a directional control valve for switching the flow direction of fluid supplied from the pressure source 60. The speed controller 52 includes a check valve 62 and a variable throttle valve 64;
6. Consists of a variable throttle valve 68.

A first port 69 is provided in the body of the flow control valve 56.
and a second port 70, each port 6
Approximately L-shaped passages 72 and 74 are provided to communicate the passages 9 and 70. A side passage 7 having a narrow diameter is provided in the lower part of the body to communicate the passage 72 and the passage 74.
6, and a variable throttle valve 78 is provided for this side passage 76.
to appear. Moreover, one relatively large chamber communicating with the passages 72 and 74 is defined, and one end of the passage 74 is formed into a tubular shape, and this tubular partition wall 7
5, a part of the coil spring 80 is fitted onto the outside. Furthermore, a diaphragm 8 integrally formed with a valve body 82 is provided.
4 is provided to divide the chamber into a first chamber 86 and a second chamber 88.
Separate and define. The valve body 82 opens and closes one end of the passage 74, and the elastic force of the coil spring 80 is applied thereto. In addition, a passage 90 and a hole 92 communicating with the chamber 88 are bored, and the hole 9
An internal thread is carved into a part of the valve body 82, and a coil spring 94 is placed on the valve body 82, and a receiving member 96 is engaged with one end of the coil spring 94.
At that time, a columnar part 98 is integrally formed on the receiving member 96, and this is inserted into the hole 92 in a slidable and airtight manner. On the other hand, the screw 101 with the handle 100 inserted therethrough is screwed into the hole 92 so as to come into contact with the columnar portion 98 . Therefore, the elastic force of the coil spring 94 can be adjusted by rotating the handle 100. Note that the valve body 82 is configured to close the passage 74 only when the fluid pressure in the chamber 88 becomes high and the difference between the fluid pressure in the chamber 86 and the fluid pressure in the chamber 86 reaches a predetermined pressure or more.

A piston 10 slides airtightly into the cylinder 58.
2 is housed inside the piston 102, and a piston rod 104 is provided which slidably projects to the outside from the piston 102. That is, the object to be transferred (not shown) is mechanically connected to the piston rod 104 and
It will be linked to 2. Holes 106 and 108 for fluid entry and exit are formed near both ends of the cylinder 58, respectively, to provide fluid passages to the chambers 110 and 112 of the cylinder 58 partitioned by the piston 102. Further, a hole 114 for introducing pressure fluid under the action of displacement of the piston 102 is bored in a side wall portion extending in the longitudinal direction of the cylinder 58. In this case, the hole 114 is bored within the stroke range of the piston 102.

Next, passages are provided to connect the above-mentioned components. That is, the switching valve 50 is provided with a passage 116 leading to the pressure source 60 and passages 118, 120 leading to the speed controllers 52, 54. Further, a passage 122 leading from the speed controller 52 to the passage 72 of the flow control valve 56 is provided,
A passage 124 is provided from the speed controller 54 to the bore 106 of the cylinder 58. Furthermore, the flow control valve 56 is provided with a passage 126 extending from the passage 90 to the hole 114 of the cylinder 58, and a passage 128 extending from the passage 74 to the bore 108 of the cylinder 58.

The cylinder device having the speed control mechanism according to the present invention is basically constructed as described above.Next, the operation and effects of the device will be explained.

First, the piston 102 in the position shown in FIG.
When moving in the direction of arrow A in the figure, the switching valve 5
Pressurized fluid from pressure source 60 to 0 is passed through passage 116
and further supplies said fluid through passage 12.
0, press fit into the chamber 110 through the speed controller 54, passage 124, and hole 106. The piston 102 is pressed by this press-fitted fluid and moves in the direction of arrow A. At this time, the chamber 112 communicates with the chamber 88 via the hole 114 and the passages 126, 90, and also communicates with the chamber 88 through the hole 108 and the passages 128, 7.
It also communicates with chamber 86 via 4. Therefore, since the fluid pressures in chambers 88 and 86 are equal, valve body 8
2 has the passage 74 open, unchanged from its original state. Therefore, fluid in chamber 112 in turn flows through hole 10
8, Passage 128, 74, Chamber 86, Passage 72, 12
2. It is sent to the outside through the variable throttle valve 64, the passage 118, and the switching valve 50. In this case, variable throttle valve 6
The moving speed of the piston 102 can be arbitrarily set by adjusting the throttle in step 4.

In this way, the piston 102 moves from its initial position in the direction of arrow A, and then the piston 102
2 passes through the hole 114. At this moment, room 110
A high-pressure fluid having a supply pressure of . The fluid introduced into the chamber 88 presses the diaphragm 84 and the valve body 82 downward in the figure, and as a result, the valve body 82 is displaced and comes into pressure contact with the tip of the annular partition wall 75, closing one end of the passage 74. occlusion (see Figure 3). In addition, since the valve body 82 is pressed in a well-balanced manner by the two coil springs 80 and 94, the quick response to changes in fluid pressure is enhanced. After the valve body 82 closes one end of the passage 74 as described above, the fluid pushed out from the chamber 112 passes through the side passage 76 whose opening degree is narrowed by the variable throttle valve 78.
The amount of fluid delivered from the piston 102 is reduced.
The movement speed of is reduced. In this case, piston 1
Since deceleration is started the moment 02 passes through the hole 114, the deceleration start position is always constant. That is, the piston 102 is not affected by changes in the load applied to the piston 102 or changes in the temperature of the fluid.
is always reliably decelerated from a predetermined position. In addition,
The degree of deceleration of the piston 102 can be freely set by adjusting the variable throttle valve 78.

Next, when moving the piston 102 from the position shown in FIG. 3 to the position shown in FIG. , to chamber 86 via passages 122, 72. At this time, relatively high pressure fluid has not been introduced into the chamber 88, so the diaphragm 84 and the valve body 8
2 is displaced upward in the figure, and the valve body 82 opens the passage 74. Therefore, the fluid supplied to the chamber 86 passes through the passages 74, 128 and the hole 108 to the chamber 11.
2, and the piston 102 is pushed by the fluid and moves in the direction of arrow B. During such a stroke, the valve body 82 is always in an open state, and the piston 102 moves smoothly to the end of the stroke. The moving speed in this case can be arbitrarily set by adjusting the throttle of the variable throttle valve 68.

As explained above, according to the cylinder device having the speed control mechanism of the present invention, the third hole is provided in the cylinder, and the third hole is defined by the diaphragm in the flow control valve via the passage. In addition to the main passage communicating with the first port and the second port of the flow control valve, a side passage is provided which communicates these ports, and furthermore, this side passage has a restriction. The valve is on display. Therefore, regardless of changes in the temperature of the fluid, changes in the frictional force on the piston, or changes in the load communicated to the piston rod, the piston is reliably decelerated from a given position during one stroke and smoothly during the other stroke. This has the remarkable effect of moving the Moreover, when the device is used to move an object back and forth and the object comes into contact with another object at one end of the movement, it is possible to reliably prevent excessive impact at that time. It will be done. Furthermore, this device has the advantage of being simpler in construction and cheaper than speed control devices using mechanically operated valves, reed switches, limit switches, etc.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design are possible without departing from the gist of the present invention. Of course.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a speed control device according to the prior art, FIG. 2 is an explanatory diagram of the entire device when the piston of a cylinder device having a speed control mechanism according to the present invention is located at one stroke end, and FIG. The figure is the second
FIG. 2 is an explanatory diagram of the entire device when the piston of the device shown in the figure is located at the other stroke end. 50...Switching valve, 52, 54...Speed controller, 56...Flow rate control valve, 58...Cylinder, 62...Check valve, 64...Variable throttle valve, 6
6...Check valve, 68...Variable throttle valve, 72,7
4... Passage, 76... Side passage, 78... Variable throttle valve, 80... Coil spring, 82... Valve body,
84...Diaphragm, 86, 88...Chamber, 94
... Coil spring, 96 ... Reception member, 10
2... Piston, 106, 108, 114... Hole.

Claims (1)

[Claims for Utility Model Registration] In a cylinder in which fluid is alternately supplied from first and second holes to both chambers partitioned by a piston of a fluid pressure cylinder to move the piston, a third hole is formed, a flow control valve is connected to the second hole and the third hole, and the flow control valve has a first port, a second port, and a passage communicating with these ports. and has first and second chambers separated by a diaphragm, the second chamber communicating with the third hole and being displaced in accordance with the operation of the diaphragm to open and close the passage. A valve body is provided integrally with a diaphragm, a first coil spring and a second coil spring are engaged with the diaphragm so that resilient forces are applied in opposite directions, and the first port and the second coil spring A side passage communicating with the two ports and facing the throttle valve is provided, and before the piston passes through the third hole, the first chamber and the second chamber are held at the same pressure under the opening action of the valve body, and the piston After passing through the third hole, supply pressure is introduced into the second chamber through the third hole, and the diaphragm closes the valve body due to the pressure difference between the first and second chambers. , and the cylinder chamber pressure on the second hole side is increased by causing the fluid in the second hole to escape through the side passage to the first port side while being throttled, thereby applying a cushioning action to the piston. A cylinder device with a characteristic speed control mechanism.