JPS6324166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mechanically operated valve installed in a circuit of a device that uses a fluid actuator to drive a movable part.

[Prior Art] Conventionally, there is a mechanically operated valve as shown in FIG. 1, for example. That is, the slide base 2 of the machine tool is advanced by the hydraulic cylinder 1, which is a fluid actuator, and the dog 3 attached to the slide base 2 comes into contact with the roller 5 of the operating rod 4, and is operated against the biasing force of the spring 6. The spool 7 integrated with the rod 4 moves downward, and as a result, the passage 10 between the pressure fluid flow ports A8 and B9 is closed, and the slide base 2 adjusts to the flow rate of pressure fluid passing through the throttle valve 14 during its forward rapid movement. When the hydraulic cylinder 1 is moved backward by switching the hydraulic circuit, the pressure fluid opens the poppet valve 13 of the check valve 12 against the biasing force of the spring 11, and flows from the pressure fluid flow port A8. It is configured such that it is sent to the cylinder 1 and the slide base 2 returns quickly.

In addition, the small chambers 16x, 16y formed by the valve body 15 and both ends of the spool 7 communicate with each other through a passage 17 formed in the spool 7 and are maintained at the same pressure, so that the spool 7 Operation rod 4
When it comes into contact with the dog 3, it slides with a small force against the biasing force of the spring 6 without being affected by hydraulic pressure.

[Problems to be Solved by the Invention] However, in this configuration, the operating rod 4 and spool 7 may become twisted or eccentric due to lateral force, and smooth movement of the operating rod 4 and spool 7 may not be possible. was sometimes damaged.

It is an object of the present invention to obviate the above-mentioned disadvantages of the prior art by providing a mechanically operated valve capable of smoothing the movement of the operating rod and spool.

[Means for Solving the Problems] That is, the gist of the present invention is to provide a pressure fluid flow port A connected to an actuator and a pressure fluid flow port A that is selectively connected to a low pressure section or a pressure source by switching an external switching valve. A valve body that receives an external operating force in the axial direction and moves forward against the biasing force of a spring and moves backward in response to the biasing force of the spring is stored in the valve body housing hole of the valve body equipped with the port B. In a mechanically operated valve that controls the amount of pressure fluid flowing between the pressure fluid flow ports A and B by controlling the amount of contraction of a throttle portion formed by the valve body and the valve body, both ends are slidable. an externally operable operating rod that is movably supported by the valve body and inserted into a through hole formed in the axis of the valve body to transmit the external operating force to the valve body; Two liquid chambers formed by the housing hole and the end surfaces of both ends of the valve body are formed in a cylindrical gap formed by the outer circumferential surface of the operating rod and the inner circumferential surface of the through hole of the valve body. The fluid chamber communicates with the pressure fluid flow port A.
Alternatively, there is provided a mechanically operated valve characterized in that a passage communicating with B is formed.

[Example] The configuration of an example of the present invention is shown in Figs. 2 to 5 below.
This will be explained using figures.

In FIG. 2, the valve body 18 of the mechanically operated valve K has a pressure fluid flow port A19 connected to the front chamber 1a of a hydraulic cylinder E as an actuator, and a pressure fluid flow port A19 connected to the rear chamber 1b via an external switching valve G. Pressure fluid flow port B2
0 is set. A spool 23 as shown in FIG. 3, which serves as a valve body and is urged upward by a spring 22, is housed in the valve body housing hole 21 of the valve body 18 in a reciprocating manner and in an extremely tightly fitted state. As the spool 23 reciprocates, the constriction portion 43 consisting of the valve body 18, the notch 24 formed on the outer periphery of the spool 23, and the small diameter portion 25 of the spool 23 is constricted or opened, and the pressure fluid communication ports A19, B
The effective cross-sectional area of the pressure fluid flow passage between the two is configured to change. At the axis of the spool 23, an operating rod 30 is slidably supported on the lids 28 and 29 of the valve body 18, which has packing 32 for preventing liquid leakage and a dust seal 31 for dust intrusion at both ends. A gap 42 is provided in the through hole 23a of 23.
The lid parts 28 and 29 are sealed with a packing 26, and the valve body 18 is secured with a bolt 27.
is fixed as one piece.

The upper end of this operating rod 30, that is, the upper lid portion 2
A portion protruding from 8 is provided with a head 33 in which a recess 34 is formed. A spherical body 35 is attached to the recess 34 via a bear link ball 36 so as to be able to rotate smoothly, and comes into contact with a dog 3a attached to a slide base 2a driven by a hydraulic cylinder E. It should be noted that the upper end surface of the spool 23 is in contact with the stepped portion 37 of the operating rod 30,
is urged upward by the urging force of the spring 22,
In addition, when the stepped portion 37 is in contact with the upper lid portion 28, the upward movement position is restricted, and at least the portions that come into sliding contact with the lid portions 28 and 29 are formed to have the same outer diameter.

In the operating rod 30 and spool 23 that are separated from each other in this way, the liquid chambers 38 and 39 formed by the upper and lower end surfaces of the spool 23 and the inner periphery of the valve body housing hole 21 are formed in the spool 23. The horizontal hole 40, the upper groove 41 shown in FIG. 4, the inner peripheral surface 23b of the spool 23 and the outer peripheral surface 3 of the operating rod 30.
A cylindrical loose fitting gap 42 formed by
The pressure is maintained at the same pressure by the pressure liquid flow port B20.
is communicated with. Further, the valve body 18 is provided with a check valve 44 for bypassing the throttle portion 43 of the spool 23 when switching the hydraulic circuit.

In the check valve 44, the valve body 46a of the poppet valve 46 is pressed against the valve seat 46b through the urging force of the spring 45, thereby closing the bypass passage 47. Further, even when the throttle part 43 is completely closed, a throttle valve 48 is provided as shown in FIG. Very slow and low speed operation is possible.

In this embodiment, the sealing packing 26 between the valve body 18 and each of the lids 28 and 29 is provided in planar contact with each of the lids 28 and 29. Therefore, even if a machining error occurs in the convex portions 60 and 61 that fit into the operating rod insertion hole 62 of the lid portions 28 and 29 and the valve body housing hole 21 of the lid portions 28 and 29, the convex portion 60 , 61 are made slightly smaller than the diameter of the valve body housing hole 21, the operating rod 30 can be slidably finely adjusted and assembled, and moreover, sealing can be performed reliably. And also, the lid part 28
As shown in FIG. 6, if the head 57 for attaching the sphere 56 is installed separately from the operating rod 55 supported by the lid 54, the lateral direction applied to the head 57 can be removed. This can prevent the force from being transmitted to the operating rod 55.

Next, the operation of the embodiment will be explained. In addition, FIG. 7 is used in conjunction with FIG. 2 to clarify the flows X, Y, and Z of the pressure liquid.

In the mechanically operated valve K configured as described above, pressure fluid is supplied to the rear chamber 1b of the hydraulic cylinder E, and the pressure fluid in the front chamber 1a flows into the pressure fluid flow port A19, causing the throttle portion 43 in the fully open state to flow. Through the pressure flow outlet B20
When the liquid flows out from the air and is discharged to the low pressure part, the slide base 2a moves forward rapidly. (Indicated by the solid line It moves downward together with the spool 23 against the biasing force of the spring 22. Therefore, the throttle portion 43 is closed, and the flow rate of the pressure fluid flowing from the pressure fluid flow port A19 to the pressure fluid flow port B20 is suppressed. At this time, adjust the throttle valve 48 to flow the pressure fluid from the pressure fluid flow port A19 to the throttle 4.
The slide base 2a operates at a low speed (cutting feed) by allowing the pressure flow to flow out from the pressure flow opening B20 through the notch 50 of No. 9 and the annular passage 20a.
(This is indicated by the broken line Y in FIG. 7.) When the spool 23 moves downward (in the valve closing direction), a portion of the pressure fluid passing through the mechanically operated valve K flows through the horizontal hole 40 of the spool 23 and into the gap. 42,
The upper and lower liquid chambers 3 of the spool 23 pass through the horizontal groove 41.
8 and 39 are filled with the same pressure as the pressure fluid flow port B20, and the pressure receiving areas at both ends of the spool 23 are the same, so the axial force applied to the spool 23 by the pressure fluid is balanced. There is. In addition, the spool 23 is separated from the operating rod 30, and the operating rod 30 is loosely fitted into the through hole 23a formed at the axis of the spool 23 with a cylindrical gap 42. The directional component force is applied to the operating rod 30, and the operating rod 30
The outer diameter of the operating rod 30 can be easily reduced to the extent that it can withstand the vertical force applied to the operating rod 30 without worrying about it becoming twisted or eccentric, and at the same time can be used for sealing the operating rod 30. It is also possible to use smaller packing 32 and dust seal 31, and therefore the starting resistance and sliding resistance of the operating rod 30 can be reduced. Therefore, the operating rod 30 moves smoothly when only the operating force that is substantially equal to the spring pressure of the spring 22 is applied, and it is also possible to control a large flow of pressure fluid with a small operating force, improving the response of the circuit. .

Next, when the hydraulic circuit is switched in the above-described state and pressure fluid is added to the pressure fluid flow port B20, the pressure fluid passes from the pressure fluid flow port B20 through the check valve 44 and through the annular flow path 19a. Since the fluid flows to the flow port A19, the slide base 2a quickly returns together with the hydraulic cylinder E, and at the same time, the dog 3a comes off from the sphere 35 of the operating rod 30 during the quick return.

Then, the upper and lower liquid chambers 38, 39 of the spool 23 are communicated with the pressure liquid flow port B20 at the same pressure, and the pressure is balanced, so the spool 23 is not subjected to the operating force by the pressure liquid and the spring 22 is activated. Due to the biasing force, it quickly returns to the upward position together with the operating rod 30. (Indicated by the dashed line Z in FIG. 7.) In this embodiment, the mechanically operated valve K is used as a deceleration valve, but by changing the mounting, the shape of the dog 3a, the spool 23, etc. It can also be easily used as a speed increasing valve. Furthermore, the passages leading to the two liquid chambers 38 and 39 at both ends of the spool 23 may be connected to the pressure fluid flow port A19 instead of the pressure flow flow port B20.

[Effects of the Invention] As explained above, in the mechanically operated valve of the present invention, the valve body such as a spool and the operating rod are separated, and the operating rod is inserted into the through hole formed in the axis of the valve body. Both ends of the valve body are slidably supported, and the two liquid chambers at both ends of the valve body formed in the valve body housing hole are communicated with the pressure liquid flow port A or B via a passage. Since the structure is configured to keep the pressure balanced, when the operating rod moves forward with the valve body due to an external operating force or when it moves back together with the valve body due to the biasing force of the spring, the pressure fluid acts on both end faces of the valve body. It becomes possible to effectively avoid the acting force. As a result of creating pressure equilibrium between the two liquid chambers, the force required to operate the valve is almost only the force that opposes the biasing force of the spring, improving the response of valve operation and reducing the slide base accordingly. No unnecessary reaction force is transmitted to the slide base, etc., and the accuracy of various processing performed on the slide base is not deteriorated.

Furthermore, the two liquid chambers are communicated through a cylindrical gap formed by the outer circumferential surface of the operating rod and the inner circumferential surface of the through hole of the valve body, and the pressurized liquid flow port A Or, since a passage communicating with B is formed, even if a lateral component force is applied to the operating rod or valve body due to an external cause or due to machining or installation accuracy during movement of the operating rod or valve body, the above-mentioned gap can be maintained. This has the effect of effectively preventing deformation and eccentricity of the operating rod and valve body, and at the same time allows greater allowances for processing the lid and mounting accuracy of the lid, operating rod, and valve body than conventional ones. be able to.

In addition, it may cause the operating rod to become distorted.
Since there is no eccentricity, the outer diameter of the operating rod can be made thinner, and at the same time, the packing and dust seals used to seal the operating rod can also be made smaller. The starting resistance and sliding resistance of the operating rod can also be reduced. Therefore, the operating rod can move smoothly forward by applying only an operating force that counteracts the spring pressure of the spring, and it is also possible to control a large amount of pressurized fluid with a small operating force, improving the response of the circuit.

Furthermore, by providing a horizontal hole in the spool,
The gap is between the liquid chambers at both ends of the valve body and the pressure liquid communication port A or B.
It has characteristics such as being able to be used as a passageway communicating with

[Brief explanation of the drawing]

Figure 1 is a principle diagram showing a conventional mechanically operated valve, Figure 2
The figure is an explanatory diagram showing a partially cutaway embodiment of the present invention, Figure 3 is a front view showing the spool, Figure 4 is a plan view of Figure 3, and Figure 5 is taken along line XX in Figure 2. FIG. 6 is an enlarged fragmentary view showing essential parts of another embodiment of the present invention, and FIG. 7 is an explanatory view showing the flow of pressurized liquid. 19...Pressure fluid flow port A, 20...Pressure fluid flow port B, 22...Spring, 23...Spool, 2
4...Notch, 28, 29, 54...Lid, 3
0,55...Operation rod, 37...Stepped part, 3
8, 39...liquid chamber, 40...horizontal hole, 41...horizontal groove, 42...gap, 43...throttle portion, 51...valve body.

Claims (1)

[Claims] 1. The shaft is inserted into the valve body housing hole of the valve body, which is equipped with a pressure fluid flow port A that is connected to the actuator and a pressure fluid flow port B that is selectively connected to a low pressure section or a pressure source by switching the external switching valve. A constriction portion formed by the valve body and the valve body, which houses a valve body that moves forward against the biasing force of a spring in response to an external operating force in the direction, and moves backward in response to the biasing force of the spring. A mechanically operated valve that controls the flow rate of pressure fluid between the pressure fluid flow ports A and B by controlling the amount of contraction of the pressure fluid flow ports A and B, wherein both ends are slidably supported by the valve body and the shaft of the valve body An operating rod that can be externally operated is inserted into a through hole formed in the core and transmits the external operating force to the valve body, and a two-piece valve body formed by the valve body housing hole and the end faces of both ends of the valve body is provided. The two liquid chambers are communicated through a cylindrical gap formed by the outer circumferential surface of the operating rod and the inner circumferential surface of the through hole of the valve body, and from the liquid chamber to the pressure liquid flow port A or B. A mechanically operated valve characterized by forming a passage communicating with the.