JPH0520884Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air cylinder device having a speed control mechanism, and more specifically, when performing a predetermined operation using a fluid pressure cylinder, the piston within the cylinder is rapidly moved to a predetermined position. The present invention relates to an air cylinder device having a speed control mechanism that is configured to stop effectively and without impact at the end of a stroke, even in the case 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 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 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 its tip end located in a space defined in the center of the valve 33. It faces to define a side road 34. On the other hand, aisle 1
2, a passage 40 is branched on the way, and a variable throttle valve 42 and a check valve 4 are installed at one end of this passage 40.
A speed controller 46 consisting of 4 is provided. Furthermore, the speed controller 46
A passageway 48 communicating with the chamber 28 is connected thereto.

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 introduced 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, 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, 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 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 a space within the stroke range of the piston, so that during one stroke of the piston, the piston The structure is configured to introduce a relatively high-pressure fluid led out from the hole after passing through the hole into the passage of the fluid pushed out from the cylinder, thereby reliably decelerating the piston from a predetermined position. It is an object of the present invention to provide an air cylinder device having a speed control mechanism that prevents excessive impact from occurring at the terminal end and ensures stroke reproducibility.

In order to achieve the above object, the present invention provides an air cylinder device that moves the piston by alternately supplying compressed air to a first chamber and a second chamber of a cylinder partitioned by a piston. a first chamber defined in a side wall of the cylinder for supplying compressed air from a compressed air source to the first and second chambers, respectively, through first and second passages;
a second hole, and a third hole defined adjacent to the second hole, communicating with the first chamber of the piston and opening on the outer peripheral surface of the piston, the piston a flow path in the piston that communicates the first chamber and the third hole when the opening of the outer peripheral surface reaches the third hole when the second chamber moves toward the stroke end side; , a branch passage that branches from a second passage that communicates with the second chamber of the cylinder and communicates with the third hole; a check valve and a variable throttle valve that are interposed in series in the middle of the branch passage; A first passage connected to the compressed air supply source and communicating with the first chamber of the cylinder, and a second passage communicating with the second chamber.
A switching valve connected to the passage and configured to switch supply of compressed air to the first passage and the second passage.

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

The air cylinder device having the speed control mechanism of this embodiment includes a switching valve 50 and a speed controller 5.
2, 54, a check valve 56, a variable throttle valve 58, a fluid pressure cylinder 60, and a passage connecting to the above components. The switching valve 50 is a valve for controlling the flow direction of fluid supplied from the pressure source 62. Speed controller 52, 54
are check valves 64 and 68 and variable throttle valve 6, respectively.
It consists of 6,70.

A first hole 72 and a second hole 74 for fluid entry and exit are provided near both ends of the cylinder 60, and a piston 78 (described later) is formed in a side wall extending in the longitudinal direction of the cylinder 60. A third hole 76 is drilled for leading out the fluid under the action of displacement. A piston 78 that airtightly slides inside the cylinder 60 is formed relatively thick in the sliding direction, and has an annularly extending recess 77 formed on its outer peripheral surface. Further, holes 79a and 79b are formed from one end surface of the piston 78 to communicate with the recess 77. The piston 78 separates the inside of the cylinder 60 into a chamber 80 and a chamber 82, and this piston 78 opens the holes 79a and 79 at a predetermined position in its displacement stroke.
b and the chamber 8 through a flow path consisting of the recess 77.
0 and 82 are communicated with each other. A piston rod 84 is fixed to the center of one end surface of the piston 78,
This piston rod 84 is led out from one side of the cylinder 60 in an airtight and slidable state. That is, the object to be transferred (not shown) is mechanically connected to the piston rod 84 and interlocks with the piston 78. In this case, the piston 78
2 and the hole 74. Therefore, the hole 76 opens within the stroke range of the piston 78.

The switching valve 50 also has a passage 8 leading to the pressure source 62.
Further, a passage 88 from the switching valve 50 to the speed controller 52 and a passage 90 from the switching valve 50 to the speed controller 54 are provided. A passage 92 leading from the speed controller 52 to the hole 72 of the cylinder 60
A passage 94 from the speed controller 54 to the hole 74 of the cylinder 60 is provided. Said passage 9
4 is provided with a passage 96 that branches off from the middle, and a check valve 56 and a variable throttle valve 58 are connected to one end of this passage 96. Furthermore, the variable throttle valve 58
A passage 98 is provided from the cylinder 60 to the bore 76 of the cylinder 60.

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

First, when moving the piston 78 at the position shown in FIG. 2 to the right in the figure, pressurized fluid from the pressure source 62 is introduced into the switching valve 50 through the passage 86. In this case, the fluid is introduced into chamber 80 via passage 88, speed controller 52, passage 92, and hole 72. The introduced fluid pushes the piston 78 to move in the direction of arrow A. Therefore, the fluid in the chamber 82 is led out of the cylinder 60 through the holes 74 and 76. The fluid led out from the hole 76 passes through the passage 98, the variable throttle valve 58, the check valve 56, the passage 96, and then the passage 94.
and reaches the speed controller 54 together with the fluid led out from the hole 74 . The fluid that has reached this speed controller 54 is controlled by the variable throttle valve 7
0, is sent out to the outside of the cylinder device via the passage 90 and the switching valve 50. In this manner, piston 78 is moved by the fluid forced into chamber 80 and
Since the fluid in the chamber 80 is sent out to the outside, the fluid pressure in the chamber 80 becomes higher than the fluid pressure in the chamber 82. In this case, the moving speed of the piston 78 can be freely set by adjusting the throttle of the variable throttle valve 70.

In this way, the piston 78 moves from its initial position to the right in the figure, and then, as shown in FIG. 3, the piston 78 reaches the hole 76 and the hole 76 and the recess 77 communicate. that moment,
The relatively high pressure fluid in chamber 80 is introduced into passage 94 through holes 79a and 79b, recess 77, hole 76, passage 98, variable throttle valve 58, check valve 56, and passage 96. Therefore, the fluid pressure within passageway 94 is higher than initially, resulting in chamber 8
2 fluid pressure increases. Eventually, the high pressure fluid in the chamber 82 acts as a cushion against the movement of the piston 78, so that the piston 78 is decelerated. In this way, deceleration of the piston 78 is started when the piston 78 reaches the hole 76 and the hole 76 and the recess 77 of the piston 78 communicate with each other.
That is, the deceleration start position of the piston 78 is always constant without being affected by changes in the load applied to the piston 78 or changes in the temperature of the fluid. The relatively high-pressure fluid introduced into the chamber 82 under the adjustment action of the variable throttle valve 58 is confined within the narrow chamber 82 defined by the piston 78, and a portion of the fluid is trapped in the narrow chamber 82 defined by the variable throttle valve 78. 4, the piston 78 is further decelerated, and finally the decelerated piston 78 stops without impact at the predetermined stroke end shown in FIG.
At this time, since the hole 76 is closed by the outer circumferential surface of the piston 78, the fluid in the chamber 80 is not led out to the outside. Therefore, a situation in which fluid continues to be discharged to the outside of the air cylinder device after the piston 78 stops is avoided, and as a result, it is possible to efficiently utilize the fluid supplied from the pressure source 62. Note that since the fluid introduced into the passage 94 from the hole 76 passes through the variable throttle valve 58, the degree of deceleration of the piston 78 can be arbitrarily set by adjusting the variable throttle valve 58.

On the other hand, when moving the piston 78 from the position shown in FIG. 4 to the position shown in FIG.
The fluid supplied to the chamber 82 is introduced into the chamber 82 through the passage 90, the speed controller 54, the passage 94, and the hole 74. This introduced fluid causes the piston 7 to
8 is pushed and moved in the direction of arrow B. In this case, the fluid delivered from the chamber 80 is
Therefore, the moving speed of the piston 78 can be freely set by adjusting the throttle of the variable throttle valve 66.

As explained above, according to the air cylinder device having the speed control mechanism according to the present invention, during one stroke of the piston, the piston moves rapidly and then is reliably decelerated from a predetermined position. Therefore, when an object is moved using the stroke and the object comes into contact with another object and comes to a stop, it is possible to reliably prevent an excessive impact when the object comes into contact with another object. Furthermore, since the device has a simple configuration, it also has the advantage of being cheaper than various speed control devices for hydraulic cylinders.

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, and FIG. 2 is an explanatory diagram of the entire device when the piston of an air cylinder device having a speed control mechanism according to the present invention is located at one stroke end. Figure 3 is an explanatory diagram of the entire apparatus when the piston of the apparatus shown in Figure 2 moves to the other stroke end side;
The figure is a partially omitted explanatory diagram of the device shown in FIG. 2 when the piston is located at the other stroke end. 50...Switching valve, 52, 54...Speed controller, 56...Check valve, 58...Variable throttle valve, 60...Fluid pressure cylinder, 62...Pressure source,
64...Check valve, 66...Variable throttle valve, 68...
...Check valve, 70...Variable throttle valve, 72, 74,
76...hole, 78...piston, 80, 82...
...Chamber, 84...Piston rod.

Claims (1)

[Claims for Utility Model Registration] Cylinder 60 partitioned by piston 78
In an air cylinder device that moves the piston 78 by alternately supplying compressed air to a first chamber 80 and a second chamber 82 of Compressed air is supplied from the compressed air supply source 62 to the first chamber 80 and the second chamber 8 through passages 92 and 94.
first and second holes 72 for supplying the
74; a third hole 76 defined adjacent to the second hole 74; a third hole 76 communicating with the first chamber 80 of the piston 78 and opening on the outer circumferential surface of the piston 78; moves toward the stroke end side of the second chamber 82 and the opening of the outer peripheral surface reaches the third hole 76, the first chamber 80 and the third hole 7
A flow path 79 in the piston 78 that communicates with the piston 6
a, 79b, 77, and a second chamber communicating with the second chamber 82 of the cylinder 60.
a branch passage 98 that branches from the passage 94 and communicates with the third hole 76; a check valve 56 and a variable throttle valve 58 that are interposed in series in the middle of the branch passage 98; and the compressed air supply source 62. A first passage 92 and a second passage 92 connected to and communicating with the first chamber 80 of the cylinder 60
A switching valve 50 connected to a second passage 94 communicating with the chamber 82 and switching the supply of compressed air to the first and second passages 92, 94. Air cylinder device.