JPH0320603B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a directional control valve with a pilot check function that controls an actuator that pushes up a heavy object, such as a cylinder, and is particularly directed to an ultra-compact, fast-response, and inexpensive pilot check valve. Regarding directional valves with functions.

[Conventional technology]

Conventionally, as this type of directional control valve, for example, the second
There is something like the one shown in the figure. In FIG. 2, a heavy object W is pushed up by a cylinder 44. Check valve 42
is an electromagnetic directional control valve 4 which can be controlled from the outside and has a spool control valve driven by an electromagnetic solenoid.
1. The pressure oil from the pressure source P' and the return oil from the tank T' are controlled by an electromagnetic four-way switching valve 43. That is, when the electromagnetic four-way switching valve 43 is energized, pressure oil flows from the pressure source P' into the cylinder 44 through the check valve 42 and pushes up the heavy object W. Once demagnetized, the heavy load W is held in its current state by the non-return force of the check valve 42. Next, when the electromagnetic directional control valve 41 is energized, the check valve 42 is opened by the pilot pressure oil, and the return oil from the cylinder 44 returns to the tank T' and the heavy object W is lowered by its own weight. When demagnetized, the check valve 42 returns to the checked state.
In this way, the heavy object W can be controlled up and down.

[Problem that the invention seeks to solve]

However, such a conventional check valve 4
In the case of a directional control valve with a pilot check function consisting of a directional control valve 2 and an electromagnetic directional control valve 41, the electromagnetic directional control valve uses a spool type control valve, and is connected to a separate pilot check valve by piping. Therefore, it takes time for the pilot check to operate due to the inflow of the pilot pressure oil, which is the operation signal from the electromagnetic directional control valve 41, and the volume of the pilot chamber is also large, so there is a delay in the rise of the pilot pressure oil, which is the operation signal. There is. In addition, the spool-type switching valve requires a wrapping margin on the land portion of the spool, which causes a delay in response. Due to these factors, the response speed was slow. Furthermore, check valve 4
2 and the electromagnetic directional control valve 41, for example, 150 mm in length and 100 mm in width.
There is an extremely high demand for a low-cost, ultra-compact directional control valve with a pilot function that can be housed in a small volume of approximately 60 mm and depth, and cannot be satisfied by conventional combinations of hydraulic equipment with independent structures for each function. It was hot.

[Purpose of the invention]

Therefore, in the present invention, the spools are changed to poppets as the functional members forming the electromagnetic directional control valve and the pilot check valve, and the piping is done as much as possible in the oil passage in a small block of, for example, about 50 mm cubic.
The center axes of the poppet, pilot piston, and check valve are all aligned with the center axis of the inner hole of the block, and the size is reduced so that all the members can be integrated and accommodated in the inner hole of the block. The purpose of this invention is to miniaturize a directional valve with a pilot check function and increase its response speed.

[Means for solving problems]

In order to achieve such an objective, the present invention
The block 15 has a P port for a pressure source, a T port for a tank, and an A port and a B port for connection, which are open on the surface thereof, and a cylindrical inner hole 31 in the center of the side surface, and a cylindrical inner hole 31 is provided in the center of the side surface. Electromagnetic solenoid 1, seat 10 and annular guide 1
A spherical check valve 12 held in a liquid chamber within 1.
and a piston 9 slidably housed in a liquid chamber in the inner hole of the sleeve 7 that opens and closes the check valve 12 between the solenoid 1 and the check valve 12;
The oil passage 8 communicating with the oil chamber of the piston 9 is connected to the sleeve 3 by the electromagnetic drive of the electromagnetic solenoid 1.
a line contact type balanced poppet 2 that slides through the inner hole of the line contact type balanced poppet 2 to be connected to the P port or the T port;
The guide 11, the sleeves 7, 3, the seat 10, and the guide 11 are arranged so that each center axis is connected to the inner hole 3.
A directional control valve with a pilot check function is integrated and housed integrally in the inner hole 31 so as to coincide with the central axis of the valve. Therefore, since all the members operate within the same block, the response time can be reduced to about 1/3 of that of the conventional system.

〔Example〕

Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment in which a directional control valve with a pilot function according to the present invention is used to control a cylinder that lifts up a heavy object.

In FIG. 1, the block 15 has ports P, T, A, and B that open on the surface thereof, and a cylindrical inner hole 31 in the center thereof. 7, seat 10, guide 11 and plug 16
(a) The electromagnetic solenoid 1 has its support portion connected to the inner hole 3.
(b) The sleeve 3 has an annular groove on its circumference and an oil passage 34 leading from the annular groove to the inner hole of the sleeve, (c) The poppet 2 is attached to the inner hole of the sleeve. The balance is held by the electromagnetic solenoid 1 and is in line contact with the edge 17 of the side surface of the sleeve 3 in contact with the spacer 6 by the pressure of the spring 4, closing the oil passage 34 leading to the port P via the oil passage 5. (d) The spacer 6 has a through hole inside, which opens into oil passages 8 and 13 provided in the sleeve 7, and when the electromagnetic solenoid 1 is actuated, the poppet 2 is connected to the spring 4. compress and spacer 7
(e) The sleeve 7 holds the spring 4 on the end surface in contact with the spacer 6, and opens on the other end surface in contact with the sheet 10 to open the oil path. 8, the piston 9 is accommodated in the inner hole, and an annular groove is provided at two locations on the circumference. (f) The piston 9 advances to the seat 10 to pilot drive the check valve 12 and has a land diameter larger than the diameter of the hole in the seat 10. (g) The two sheets 10 form a liquid chamber through an annular guide 11, and two spherical check valves 12 are held in the liquid chamber, (h) The guide 11 is arranged on the circumference. (i) The plug 16 is screwed into the other end of the inner hole 31, and the protruding part of the plug 16 is inserted into the seat. (j) Poppet 2, piston 9 and check valve 1
The central axis of the inner hole 31 is made to coincide with the central axis of the inner hole 31, and the oil passage 5 connects the oil passage 34 and the port P, and the oil passage 3 connects the oil passage 35 and the port T.
6. It has a directional control valve with a pilot check function in which an oil passage 38 connecting the oil passage 18 to port A and an oil passage 37 connecting the oil passage 14 to port B are both provided in the block 15.
This directional control valve with a pilot function includes an electromagnetic four-way control valve 43 for switching the flow direction of pressure oil in the main flow path at port B, a pressure source ^P1 and a tank ^T1.
to ports P and T, cylinder 44 to port A
It is shown that they are connected to each other.

Regarding the electromagnetic solenoid 1, only the supporting part of the electromagnetic solenoid is shown, and the drive shaft and electromagnetic coil fixed to the movable piece are not shown. The same applies to the plug 16 prepared for use.

Next, the operation of the directional control valve with pilot function of the present invention will be explained. Poppet 2 is port P
With respect to the pressure oil flowing in through the oil passages 5 and 34, the pressure in the left and right direction due to the pressure oil is balanced in the balanced-shaped recess, so that it is stationary. In the illustrated state, the electromagnetic solenoid 1 is in a demagnetized state, and the poppet 2 is pushed rightward by the spring resistance of the spring 4 to make line contact with the edge 17 of the sleeve 3, thereby closing the oil passage 34. The oil passage 8 communicates with the oil passage 13 through the through hole of the spacer 6, and further communicates with the tank ^T1 via the oil passages 35 and 36 and the port T. The piston 9 returns to the illustrated position due to the check pressure of the check valve 12, and is in the check state. Therefore, the pressure oil in the cylinder 44 that communicates with the liquid chamber from the port A through the oil passages 38 and 18 does not flow out, so the cylinder 44 maintains its current position. When the electromagnetic solenoid 1 is energized, the poppet 2 comes into close contact with the end surface of the sleeve 7 while compressing the spring 4, opening the edge 17 and opening the oil passage 1 due to this close contact.
Close 3. Pressure oil from port P goes through oil lines 5 and 34.
Flowing in from the open passage of edge 17 through
It passes through the oil passage 8 and enters the liquid chamber at the bottom of the sleeve inner hole of the sleeve 7, and presses the piston 9 to the left. Since there is a difference between the pressure acting areas of the check valve 12 and the piston 9, the piston 9 moves to the left, and the drive shaft of the piston 9 advances to the seat 10 to open the check valve 12.
Pressure oil is pushed by the heavy object W to port A and oil passage 38.
It further reaches Pate B via oil passages 14 and 37, and returns to tank ^T1 through electromagnetic four-way switching valve 43. When the electromagnetic solenoid 1 is demagnetized, the check valve 12 returns to the initial pilot check state.
Next, when the electromagnetic four-way switching valve 43 is energized, the pressure oil flows from port B through oil passages 37 and 14 to check valve 1.
Push open 2 to enter the liquid chamber, and then open oil passages 18 and 38.
It flows into the cylinder 44 from the port A through the cylinder 44 and pushes up the heavy object W. When demagnetized, check valve 12
The current state is maintained by

〔Effect of the invention〕

By making the pilot check valve and the electromagnetic directional control valve that controls the pilot check valve into a pilot function directional control valve integrated into one ultra-compact block, it is possible to improve the pilot pressure oil passage. By reducing the volume of the pilot pressure oil chamber and changing the spool valve to a poppet valve, the response time has been shortened to approximately 1/3 of that of the conventional model, and the space for the directional control valve with pilot function has been reduced to meet customer requests. Therefore, the time required for processing and assembling each member was shortened, and costs could be reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view showing one embodiment of a directional control valve with a pilot function according to the present invention, and FIG. 2 is a hydraulic circuit diagram showing a conventional device. 1...Electromagnetic solenoid, 2...Poppet, 3,7...
Sleeve, 4...Spring, 6...Spacer, 9...
Piston, 10... Seat, 11... Guide, 12...
Check valve, 15...Block, 16...Plug, 1
7... Edge, 5, 8, 13, 14, 18, 34,
35, 36, 37, 38...Oil passage, 31...Inner hole, 4
1... Solenoid directional control valve, 42... Check valve, 43...
Solenoid 4-way switching valve, 44...cylinder.

Claims (1)

[Claims] 1. The block 15 is provided with a pressure source P port, a tank T port, a connection A port and a B port that are open on its surface, and a cylindrical inner hole 31 in the center, An electromagnetic solenoid 1 of an electromagnetic directional control valve, a spherical check valve 12 held in a liquid chamber in a seat 10 and an annular guide 11, and an opening/closing mechanism for opening and closing the check valve 12 between the solenoid 1 and the check valve 12. A piston 9 is slidably built into a liquid chamber in the inner hole of the sleeve 7 to be driven, and an oil passage 8 communicating with the oil chamber of the piston 9 is connected to the inner hole of the sleeve 3 by electromagnetic driving of the electromagnetic solenoid 1. Line contact type balanced poppet 2 that can be switched and connected to P port or T port by sliding.
and the guide 11, the sleeves 7 and 3, the seat 10, and the guide 11 in the inner hole 31 so that their center axes coincide with the center axis of the inner hole 31.
A directional control valve with a pilot check function, which is integrated and housed in one piece.