JP2586207Y2 - Poppet valve device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a poppet valve device used for construction machines and the like, and more particularly to a poppet valve device capable of greatly reducing shock at the time of merging.

[0002]

2. Description of the Related Art Conventionally, as a merge control device of a hydraulic control valve, for example, Japanese Utility Model Laid-Open Publication No. 48-16422 is known. That is, as shown in FIG. 3, this type of merge control device includes two control valves 16 and 18 inserted in series in a hydraulic circuit for operation by a pair of hydraulic pumps 12 and 14, and these valve A switching valve 23 is connected to one of the bypass return oil passages 25 of a check valve 20 connecting the hydraulic pumps 12 and 14 to an oil passage between 16 and 18 and a poppet-type unload valve 22 (hereinafter referred to as a poppet valve 22). The operation of two actuators (not shown) is switched between high and low speeds by unloading any one of the oil pumps 12 and 14.

[0003]

That is, in this type of merge control device for a hydraulic control valve, as shown in FIG. 3, oil passages 28 and 36 are provided in an intermediate inlet 32,
A poppet valve 22 having an orifice 34 serving as a throttle is provided between the two oil passages. The poppet valve 22 is provided with a switching valve 2 provided on a bypass return oil passage 25.
When the valve 3 is in the closed state shown in the figure, the pressure before and after the orifice 34 becomes the same pressure because there is no flow of oil from the oil passage 28 to the poppet valve chamber 26. Therefore, the poppet valve 22 is shown by the action force of the spring 38. When the switching valve 23 is in the open position, a flow from the oil passage 28 to the poppet valve chamber 26 occurs, and a differential pressure is generated around the throttle 34, as shown in FIG.
Since this differential pressure exceeds the acting force of the spring 38, the poppet valve 2
2 is moved downward, thereby allowing the oil passages 28 and 36 to communicate with each other.

However, when the switching valve 23 is returned to the closed state from such a communication state, the poppet valve 22 can still receive the hydraulic oil from the oil passage 28 to the oil passage 36 even if the area of the orifice 34 is relatively small. Is carried out in a single time, the poppet valve 22 rapidly shuts off the oil passage 28 and the oil passage 36, so that a large impact is generated in the oil passage 28.

In this case, even if the switching valve 23 is operated slowly, the position of the poppet valve 22 is determined by the balance between the differential pressure between the oil passage 28 and the poppet valve chamber 26 and the acting force of the spring 38. When the valve 22 closes, the spring 38
When the acting force becomes larger than the differential pressure across the orifice 34, it suddenly moves, causing an impact, and has a problem that a safety problem occurs at the time of merging.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a poppet valve device having an extremely simple structure and capable of greatly reducing the impact of the poppet valve at the time of merging, thereby improving the hydraulic system and operational safety. To offer.

[0007]

In order to achieve the above object, a poppet valve device according to the present invention is provided with at least two oil chambers, one bypass return line, and provided on the bypass return line. An on-off valve, a valve body provided between the two oil chambers, a poppet having a throttle between the one oil chamber and the bypass return line in the valve body, and moving the poppet to one side. In the open position of the on-off valve, a differential pressure before and after the throttle generated by a flow from the one oil chamber to a bypass line through a throttle provided on the poppet, against the spring force. By moving the poppet, the two oil chambers are communicated, and at the closed position of the on-off valve, the pressure before and after the throttle of the poppet valve becomes the same pressure, and the poppet is pressed to one side by the spring force. In the poppet valve device configured to shut off the two oil chambers, the poppet valve device is provided with a flow control unit with pressure compensation inside the poppet, and is provided from the one oil chamber via the flow control unit with pressure compensation. And pressurized oil flows into the bypass return line.

In this case, the flow control means with pressure compensation includes a poppet slidably inserted in the valve body between the one oil chamber and the bypass return line and having a throttle on one side, and a poppet in the poppet. A guide member which is slidably inserted into the guide member and is urged to one side together with the poppet via a spring; a through-hole is formed in a side wall of the guide member so as to be slidably inserted inside the guide member; A spool having a lateral hole formed in a side wall and an annular groove communicating with the lateral hole so as to coincide with the through lateral hole when one side portion having a diaphragm is pressed and positioned on the diaphragm side of the poppet via a spring capable of adjusting a pressing force. It is preferable to configure with the following.

[0009]

According to the poppet valve device of the present invention, the pressure oil is caused to flow from one oil chamber to the bypass return line via the flow control means with pressure compensation.
The impact at the time of joining by the poppet valve is greatly reduced, and thus the safety of the hydraulic device and the operation can be improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the poppet valve device according to the present invention will be described in detail with reference to the accompanying drawings. For convenience of description, the same components as those of the conventional structure shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 is a cross-sectional view of a main part of the poppet valve device according to the present invention in a closed state, and FIG. 2 is a cross-sectional view of a main part of the poppet valve device in an open state. In the figure, reference numeral 40 denotes a valve base, in which two oil chambers (hereinafter referred to as oil passages 42, 44) are formed, and a sleeve 46 is provided between the two oil passages 42, 44. Are mounted in a liquid-tight manner.

The sleeve 46 is connected to the oil passage 4
A lateral hole 45 communicating with the inside is formed in the four side wall, and a large-diameter back chamber 48 whose inner diameter is further enlarged is formed at the right end of the sleeve 46. This back chamber 48 is a bypass return communicating with the outside. It is configured to be closed by a cap 52 provided with a passage 50 as a line.

Further, a poppet 54 is slidably and liquid-tightly inserted into the sleeve 46. The poppet 54 is connected to the oil passages 42 by a partition 56 provided on one side. The large-diameter back chamber 48 is defined.

Then, one end side wall of the poppet 54 (the partition wall 5)
6), four lateral communication paths 58 are provided.
A large-diameter flange 60 is formed on the other end of the peripheral edge so as to face the inside of the back chamber 48, and a small through-hole 55 communicating with the inner diameter portion is formed in a side wall close to the flange 60.
An orifice 62 communicating with the oil passage 42 is formed in a partition wall 56 of the poppet 54, and a flow rate control unit with pressure compensation described later is provided in a hole opened on the back chamber 48 side of the poppet 54. Provided.

That is, the flow control means with pressure compensation is configured as follows. A cylindrical guide member 66 having a flange 64 formed on one side, that is, a left end portion, and a plurality of lateral holes 70 communicating with the inside thereof is formed in the side wall of the poppet 54. The outer periphery of the flange 64 is guided and slidably fitted.

The guide member 66 presses and presses the flange 64 side end against the partition 56 of the poppet 54 by the urging force of the spring 68, and moves the back chamber 48 side end inside the large diameter flange 60 end face. And the large-diameter flange 60 is brought into contact with the inner-diameter stepped portion of the sleeve 46 for axial positioning.

Further, a spool 73 is slidably and liquid-tightly inserted in the guide member 66 in an axially slidable manner. The spool 73 forms an internal passage 75 in a cylinder formed in a cylindrical cup shape. An orifice 72 serving as a throttle is provided on the left end wall, and an annular groove 74 having a U-shaped cross section is formed on the outer periphery of the side wall. A plurality of lateral holes 78 communicating with the internal passage 75 are formed in the groove 74. When the left end wall provided with the orifice 72 is brought into contact with the partition 56 of the poppet by a spring 76 so as to adjust the pressing force, the annular groove 74 and the guide member 6 are formed.
6 is configured to coincide with the horizontal hole 70.

Further, in the poppet valve device thus configured, the oil passage 42 is connected to the hydraulic pump 80, the other oil passage 44 is connected to the tank 82, and the oil passage 42 is connected to the oil passage 42.
A converging line 86 is connected via a check valve 84, and an electromagnetic on-off valve 88 is connected and arranged on the bypass return line of the passage 50 of the cap 52 communicating with the back chamber 48.

That is, in the poppet valve device, in the state shown in FIG. 1, the oil passage 42 connected to the hydraulic pump 80 is formed by the orifice 62 on one side of the poppet 54, the orifice 72 of the spool 73, and the internal passage 75 of the spool 73. The lateral hole 78 of the guide member 66 extends from the lateral hole 78 and the annular groove 74.
Through the inside of the poppet 54 to the back chamber 48, and further from the back chamber 48 to the closed solenoid valve 88 via the passage 50 of the cap 52.

The operation of the poppet valve device constructed as described above will be described in detail below. That is, as shown in FIG. 1, when the electromagnetic on-off valve 88 is held in the closed state, the pressure oil from the pump 80 on the oil passage 42 is supplied to the back chamber 48.
The oil passage 42 and the back chamber 48 have the same pressure.

Therefore, since the poppet 54 is pressed to the left in the figure via the guide member 66 by the action of the spring 68, the communication passage 58 provided in the side wall of one end of the poppet 54 is The horizontal hole 45 provided in the sleeve 46 is shut off in a liquid-tight manner, and the oil passages 42 and 44 are separated.

Next, FIG. 2 shows a case where the solenoid on-off valve 88 is automatically operated by an external signal 90 to be in an open state.
In this case, pressure oil from the pump 80 applied to the back chamber 48 flows out of the electromagnetic opening / closing valve 88 to the tank 82 through the passage 50 of the cap 52, so that the pressure in the back chamber 48 decreases.

Since the oil passage 42 is connected to the back chamber 48 through the orifice 62 on one side of the poppet 54 and the orifice 72 of the spool 73, the oil passage 42 is connected between the oil passage 42 of the poppet 54 and the back chamber 48. A differential pressure is generated in the poppet 54, and the differential pressure causes the poppet 54 to move rightward as shown in FIG. 2 against the acting force of the spring 68, so that the communication passage 58 of the poppet 54 and the lateral hole 45 of the sleeve 46 are separated. Communication, oil passage 42
Is made to flow into the oil passage 44.

In this case, the orifice 72 of the spool 73
Due to the differential pressure generated before and after, the spool 73 slightly moves rightward against the acting force of the spring 76,
The differential pressure generated at the end of the spool 73 due to the differential pressure between the spool front chamber 47 formed between the end of the spool 3 and the poppet partition 56 and the internal passage 75 of the spool 73 and the spring 76
It moves to the right and stops at a position where the action force is balanced.

Therefore, when the solenoid on-off valve 88 is operated by the external signal 90 to switch from the valve-open state in FIG. 2 to the valve-closed state in FIG. Until the passage 42 and the back chamber 48 have the same pressure, the flow of the pressure oil remains from the oil passage 42 toward the back chamber 48. That is, the orifice 62 on one side of the poppet 54 from the oil passage 42, the spool front chamber 47, the orifice 72 of the spool 73, the internal passage 75, the lateral hole 78, the annular groove 74, the lateral hole 70 of the guide member 66, the inner diameter of the poppet 54 And flows into the back chamber 48.

Here, as shown in FIG. 2 described above, by setting the acting force of the spring 76 to be balanced at the position of the spool 73 slightly moved, the spool 7
The pressure difference generated before and after the orifice 3 is also very small, and the guide member 6 in the annular groove 74 of the spool 73 is reduced.
6 can be restricted to a very small size, and the amount of inflow from the oil passage 42 to the back chamber 48 per unit time can be extremely reduced.

For this reason, the pressure oil in the back chamber 48 rises very slowly until it becomes the same pressure as the pressure oil in the oil passage 42, and the poppet 5
4, the pressure difference between the oil passage 42 side and the back chamber 48 decreases very slowly.

Here, when the acting force of the spring 68 overcomes the differential pressure, the poppet 54 which has moved rightward against the acting force of the spring 68 shown in FIG. 2 is pushed back to the left at a very slow speed, The communication passage 58 of the poppet 54 in the lateral hole 45 of the sleeve 46 is shut off at a very slow speed, and the inflow from the oil passage 42 to the oil passage 44 per unit time decreases very slowly, while the inflow finally ends. Stop.

Therefore, the electromagnetic on-off valve 88 is rapidly switched from the open position to the closed position by the external signal 90 to flow the pressure oil of the pump 80 from the oil passage 42 to the oil passage 44 to the tank 8.
2 from the oil passage 42 to the merging line 86
When the state is switched to the state of merging, the amount of inflow per unit time of the communication path 58 of the poppet 54 decreases very slowly, and accordingly, the amount of inflow into the merging line 86 increases gradually, so that merging gradually takes place. Thereby, the impact at the time of merging can be significantly reduced. The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment, and it is needless to say that various design changes can be made without departing from the spirit of the present invention.

[0029]

As described above, in the poppet valve device of the present invention, the flow control means with pressure compensation is provided inside the poppet, and the bypass return from the one oil chamber via the flow control means with pressure compensation is provided. By adopting a configuration in which pressurized oil flows into the line, the impact at the time of merging with the poppet valve can be significantly reduced with a very simple configuration, thereby improving the safety of the hydraulic system and operation. Has excellent effects.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a poppet valve device according to an embodiment of the present invention, showing a closed state of the poppet valve device.

FIG. 2 is a cross-sectional view illustrating a poppet valve device according to an embodiment of the present invention, showing a poppet valve device in an open state;

FIG. 3 is a sectional view showing a conventional example of a poppet valve device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Tank 12,14 Hydraulic pump 16,18 Control valve 20 Check valve 22 Unload valve (poppet valve) 23 Switching valve 25 Oil passage 26 Valve chamber 28,36 Oil passage 32 Intermediate inlet part 34 Orifice 38 Spring 40 Valve base 42 , 44 Oil chamber (oil passage) 46 Sleeve 47 Spool front chamber 48 Back chamber 50 Bypass return line (passage) 52 Cap 54 Poppet 56 Partition wall 58 Communication passage 62 Restriction (orifice) 66 Guide member 68 Spring 70, 78 Side hole 72 Restriction (Orifice) 73 Spool 74 Annular groove 75 Internal passage 76 Spring 80 Hydraulic pump 82 Tank 84 Back chamber 86 Merging line 88 Solenoid on-off valve

Claims (2)

(57) [Scope of request for utility model registration] At least two oil chambers, one bypass return line, an on-off valve provided on the bypass return line, a valve body provided between the two oil chambers,
A poppet having a throttle between the one oil chamber and the bypass return line in the valve body, and a spring pressing the poppet to one side, wherein the one oil chamber is in the open position of the on-off valve. The two oil chambers communicate with each other by moving the poppet against the spring force by a differential pressure across the throttle generated by a flow from the valve to the bypass return line through a throttle provided in the poppet, and the on-off valve In the closed position, the pressure of the poppet valve before and after the throttle becomes the same pressure, and the poppet is pressed to one side by the spring force to shut off the two oil chambers. The valve device is provided with a flow control unit with pressure compensation inside the poppet, and pressurized oil flows into the bypass return line from the one oil chamber via the flow control unit with pressure compensation. Poppet valve device, characterized in that configured to cause. 2. A poppet having a throttle on one side and slidably inserted in said valve body between said one oil chamber and a bypass return line, and a pressure control means provided in said poppet. A guide member slidably inserted and urged to one side together with the poppet via a spring, a through hole formed in a side wall of the guide member, and a slidably inserted and slidably inserted inside the guide member. A spool formed with a lateral hole in the side wall and an annular groove communicating with the lateral hole so as to match the through lateral hole when one side formed with the pressure is pressed and positioned on the throttle side of the poppet via a spring capable of adjusting the pressing force. The poppet valve device according to claim 1, wherein the poppet valve device comprises: