JP4823673B2 - Hydraulic circuit with shockless valve - Google Patents

Description

The present invention, beauty chair, dental chair, built in the hydraulic circuit for vertically moving the operating table or the like to a hydraulic circuit connected shea Yokkuresu valve to reduce the shock generated when starting and stopping the hydraulic equipment.

Conventionally, as an example of a hydraulic circuit for reducing a shock at the time of up-and-down movement of a barber / dental chair, dental chair, and operating table (hereinafter simply referred to as a chair), a proportional control solenoid valve is incorporated in the hydraulic circuit. A control device that controls the amount of oil to the hydraulic cylinder or the amount of oil discharged from the hydraulic cylinder by changing the voltage with respect to the chair to control the ascending and descending speed of the chair (for example, Japanese Patent Laid-Open No. 9-126348). There is another example in which an accumulator is incorporated in a hydraulic circuit, and oil from a hydraulic device is once stored in the accumulator and supplied to the hydraulic cylinder from the accumulator.
JP-A-9-126348

  By the way, in the case where the proportional control solenoid valve is incorporated in a hydraulic circuit to control the hydraulic cylinder, the speed of raising and lowering the chair can be controlled by controlling the voltage applied to the proportional control solenoid valve, and The shock at the start and stop of lifting and lowering can be alleviated, but because the opening degree of the valve is controlled by the balance force of electromagnetic force and return spring, variation is likely to occur, and the valve parts are high There is a problem that accuracy is required and adjustment work at the time of assembling work becomes difficult, resulting in an increase in cost and a complicated and expensive control circuit.

  On the other hand, even if the accumulator is incorporated in the hydraulic circuit, it is possible to reduce the shock at the start and stop of lifting, but the degree of relaxation of the shock varies depending on the weight difference of the person sitting in the chair and the stop There was a problem that the sitting person was given a fluffy sensation by moving up and down, although slightly.

The present invention is intended to solve the above-described problems, and the object of the present invention is to reduce the shock at the time of lifting and lowering by incorporating it in a known general hydraulic circuit, and to manufacture at a low cost, and Since it can be driven by simple on / off control without requiring an advanced control circuit, the cost of the entire hydraulic circuit can be reduced, and the ram discharge and storage shocks in the cylinder can be taken with a single valve. in which St. provide a hydraulic circuit connected to the can Cie Yokkuresu valve.

The hydraulic circuit to which the shockless valve according to the present invention is connected is intended to achieve the above-mentioned purpose, and the means of claim 1 is connected to a valve for supplying and discharging oil to a hydraulic cylinder that moves up and down by hydraulic pressure. In each of the hydraulic circuits, a coil, a stator positioned and fixed inside the coil, an upper housing positioned in the coil, and the upper housing are integrally formed at each hydraulic cylinder outlet / inlet. A housing formed of a lower housing in which first and second flow paths in which ports for inflow and outflow of oil are formed are formed and a communication hole communicating with the upper housing is formed; A plunger composed of an inner peripheral surface and a large-diameter portion that moves through a gap and a valve portion that moves in the communication hole, and a method for separating the plunger from the stator To be composed of a spring biasing springs, oil moves to the lower oil reservoir of the plunger upon movement of said plunger upon energizing the coil from the upper oil reservoir of the plunger through the gap, Further, the during movement of the plunger by the spring which connects the shockless valve plunger in the oil moves to the upper part oil sump through the gap from the lower part oil sump moves slowly Features.

  In the present invention, as described above, the oil reservoir is formed at the upper and lower ends of the plunger, and a gap is formed between the outer peripheral surface of the plunger and the inner peripheral surface of the housing so that oil can flow. So that when the plunger is moved by the spring force of the spring and when the plunger is energized, oil flows from one oil reservoir to the other oil reservoir via the gap so that the plunger moves gently. Therefore, since the oil to the cylinder is slowly supplied or discharged, the shock of starting and stopping when the chair is raised and lowered can be alleviated.

  In addition, since the plunger valve part can be displaced in the communication hole and the valve hole is closed by hydraulic pressure, the clearance between the plunger valve part and the communication hole can be increased, and therefore the accuracy of parts is not required. The effect is that the cost can be significantly reduced.

  In the present invention, the large-diameter portion of the plunger is movably accommodated in the upper housing, and accumulates on the upper and lower surfaces of the large-diameter portion when the coil is energized and when the plunger is moved by the spring force of the spring. The plunger moves slowly up and down by the movement of oil.

An embodiment of a shockless valve A used in the hydraulic circuit of the present invention will be described below with reference to FIGS.
1 is a cylindrical coil, 2 is a stator fitted and fixed to the upper end of an upper housing 42 to be described later, and an air vent hole 21 and a screw hole 22 are formed in communication with the hole 21 at the center. Reference numeral 3 denotes a cover fixed in a state of covering the coil 1 and is fixed to the stator 2 by screws 31. A hard ball 23 is positioned on the bottom surface of the screw hole 22, and the air vent hole 21 is closed by tightening the screw 31, but air that accumulates in an oil sump G that will be described later by loosening the screw 31. Can be pulled out.

  Reference numeral 4 denotes a housing made of a non-magnetic material such as copper fixed to the lower portion of the integrated coil 1. The housing 4 includes a lower housing 41 and an upper housing 42, and screw holes 41 a formed in the lower housing 41. The upper housing 42 is integrated by screwing the outer peripheral screw 42a. Reference numeral 43 denotes an O-ring for preventing oil leakage from the screw portions of the upper and lower housings 41 and 42.

  The lower housing 41 is provided with first and second flow paths 41b and 41c for inflow and discharge of oil from a motor pump (not shown) on the same plane. Further, the lower housing 41 is formed with a bottomed communication hole 41d orthogonal to the first and second flow paths 41b and 41c, and the communication hole 41d and the first and second flow paths 41b. , 41c are formed with ports 41e, 41f.

  Furthermore, the upper housing 42 is formed with an accommodation hole 42b that communicates with the communication hole 41d and accommodates a large-diameter portion 51 of the plunger 5 described later via a gap. Reference numeral 41g denotes a valve seat that contacts the lower surface of the plunger 5 that contacts the lower limit of the plunger 5. The valve seat 41g is configured such that oil can be circulated even when the lower surface of the plunger 5 is in contact.

  5 is a plunger in which the large-diameter portion 51 is inserted in the upper housing 41 through a gap so that the large-diameter portion 51 can move up and down. The large-diameter portion 51 is formed with a spring accommodating hole 51a for accommodating the spring 6. And acting as a valve portion that plugs either of the ports 41e, 41f when hydraulic pressure is generated in the first and second flow paths 41b, 41c when inserted into the communication hole 41d through a gap. The valve part 52 to be performed is formed integrally with the large diameter part 51.

  An upper oil reservoir G1 is formed in the gap between the upper surface of the large diameter portion 51 of the plunger 5 and the lower surface of the stator 2, and the lower oil is formed in the gap between the lower surface of the large diameter portion 51 and the upper surface of the lower housing 41. A reservoir portion G2 is formed, and the oil reservoir portion G is formed by the upper oil reservoir portion G1, the lower oil reservoir portion G2, and the gap between the inner periphery of the communication hole 41d and the valve portion 52.

Next, the operation will be described based on the above-described configuration.
FIG. 1 shows a state in which the chair is stopped and the shockless valve A is not energized. In this state, the chair is in either the raised position or the lowered position. It is assumed that there is. Then, the plunger 5 is lowered by the spring 6, and, since the hydraulic pump (not shown) is stopped without moving the oil, thus, the bottom surface of the large-diameter portion 51 of plunger 5 is in contact with the valve seat 41g It is upright.

In this state, when an operation for raising the chair in the lowered position (for example, an operation of a foot pedal attached to the chair base or a switch provided on the armrest) is performed, the motor pump is energized. Is called. Here, if the motor pump is connected to the first flow path 41b side, the oil from the motor pump is supplied from the port 41e, so that the valve portion 52 of the plunger 5 is shown in FIG. As shown in FIG. 2, the port 41f is tilted so that the oil is prevented from flowing into the second flow path 41c. At this time, the gas flows into the cylinder slightly through the port 41f and the second flow path 41c, but is not lifted to the extent that the seated person feels that the chair has been lifted.

  Next, the coil 1 is energized after the energization of the motor pump, and the plunger 5 is sucked against the spring force of the spring 6. At this time, the oil accumulated in the upper oil reservoir G 1 is It moves below the lower oil reservoir G2 through the gap between the outer periphery of the large diameter portion 51 of the plunger 5 and the upper housing 42. The force to move from the upper oil reservoir G1 to the lower oil reservoir G2 becomes a load, and the plunger 5 moves gently toward the stator 2 side. Therefore, the chair begins to rise slowly. Then, as shown in FIG. 3, when the plunger 5 is completely sucked by the stator 2, the ports 41e and 41f are in communication with each other, so that the fixed amount of oil flowing between the ports 41e and 41f is constant. The chair rises at speed.

Then, when the operation for stopping the rise of the chair is performed, since the energization of the coil 1 is interrupted, but the plunger 5 starts decreasing the spring force of the spring 6, the lower oil reservoir G 2 Although it has accumulated, the oil moves to the upper oil reservoir G1. Then, as described above, the force for moving the oil becomes a load, and the plunger 5 gently descends. At this time, as shown in FIG. 2, the valve section 52 is lowered while being inclined in a direction to close the port 41f by the hydraulic pressure from the first flow path 41b, and the oil from the first flow path 41b to the second flow path 41c. Is gradually reduced and stopped, and the chair slowly stops rising. Thereafter, the power supply to the motor pump is cut off.

Next, the operation of the shockless valve A when the chair in the raised position is lowered is the same as the operation of the shockless valve A that raises the chair in the lowered position. In this case, the operation returns the oil in the cylinder from the second flow path 41c to the oil tank via the first flow path 41b.

Next, an apparatus having two hydraulic cylinders using the shockless valve A of the present invention, for example, a hydraulic circuit for raising and lowering a chair and raising and lowering a backrest in a barber / beauty chair will be described with reference to FIG. .
In FIG. 4, 71 is a motor pump, 72 is an oil tank, 73 is a relief valve, 74 is a lifting hydraulic cylinder that lifts and lowers a seat such as a barber / beauty chair, and 75 is a lifting solenoid valve that operates when the lifting cylinder 74 is raised. , 76 is a descending solenoid valve that operates when the lifting cylinder 74 is lowered, 77 is a backrest hydraulic cylinder that raises the backrest, 78 is a standing solenoid valve that erects the backrest cylinder 77, and 79 is operated when lying down. A depression solenoid valve, 80 is a throttle valve, and 81 is a check valve.

  As is well known, a switch for raising and lowering the seat and raising and lowering the back is attached to the hairdressing and beauty chair. Further, the motor pump 71 and the lift solenoid valve 75 are turned off by a delay circuit when the lift switch is turned off. The drop solenoid valve 76 is also delayed by a delay circuit when the lift switch is turned off. It is configured to be in an off state.

Next, the operation of the hydraulic circuit will be described with reference to the timing chart of FIG. In addition, although this description is about the raising / lowering operation | movement of the seat part of a barber / beauty chair, since the raising / lowering operation | movement of a backrest is the same operation | movement as the raising / lowering operation of a seat part, description is abbreviate | omitted.
First, in a state (state 1) in which none of the coil 1, the motor pump 71, the relief valve 73, and the ascending electromagnetic valve 75 is energized, when the ascent switch for raising the seat is turned on, the motor pump 71 and A current flows through the ascending solenoid valve 75 to start driving. Then, supply of oil from the oil tank 72 is started, but since the coil 1 of the shockless valve A is not energized (state 2), the oil that has passed through the ascending electromagnetic valve 75 passes through the relief valve 73. And returned to the tank 72 (state of FIG. 2).

  Next, since the coil 1 of the shockless valve A is energized, the operation shown in FIGS. 2 to 3 described with reference to the configuration of the shockless valve A is performed, and the plunger 5 is gradually opened and then fully opened ( State 3). Accordingly, the oil supplied to the elevating cylinder 74 is gradually increased, and the chair is gradually raised, and thereafter rises at a constant speed.

  Next, when the raising switch is turned off, the current to the coil 1 of the shockless valve A is cut off. In this state, the plunger 5 of the shockless valve A starts the operation shown in FIGS. At this time, a voltage is applied to the motor pump 71 and the lift solenoid valve 75 for a certain period of time even after the lift switch is turned off. Accordingly, the plunger 5 starts to slowly descend and the seat portion slowly stops to rise (state 4).

  Then, in the state where the plunger 5 has finished descending (the chair is stopped), the energization of the motor pump 71 and the ascending electromagnetic valve 76 is cut off and the initial state of FIG. 1 is restored (state 5).

  Next, when the lowering switch of the chair is operated, a voltage is applied to the lowering electromagnetic valve 76. As described in the configuration of the shockless valve A, the state (state 6) of FIG. The direction of flow is reversed) The plunger 5 starts to rise slowly. 2 to 3, the oil in the elevating cylinder 74 is gradually returned to the oil tank 72 via the descending solenoid valve 76, so that the seat portion gradually descends. It starts and then descends at a constant speed (state 7).

  When the lowering switch is turned off, the energization of the coil 1 of the shockless valve A is cut off. Therefore, as described in the operation of the shockless valve A, the operation becomes the operation shown in FIGS. Descent stops gently (state 8). At the same time, the energization of the descending solenoid valve 76 is cut off and the initial state shown in FIG. 1 is reached (state 9). In this description, the lifting / lowering operation of the seat portion of the barber / beauty chair has been described. However, since the raising / lowering operation of the backrest is the same as the lifting / lowering operation of the seat portion, the description thereof will be omitted.

  FIG. 6 shows a case in which two shockless valves A are used to control a chair by four hydraulic cylinders, for example, raising and lowering a seat, raising and lowering a backrest, raising and lowering a legrest, and raising and lowering a pillow. This is an example. In this embodiment, the two shockless valves A are divided into those for removing the shock at the time of rising and those for removing the shock at the time of lowering. As shown in the figure, one shockless valve A is directly connected to the motor pump 71, and the other shockless valve A ′ is directly connected to the oil tank 72. 6 denote the same members as those in FIG.

  In this embodiment, it is possible to start and stop slowly by the same operation as described above, but it is not possible to take a shock when simultaneously raising and lowering two or more cylinders. Since it is possible to take a shock when raising and lowering only one cylinder at different times, the hydraulic circuit is convenient for reducing the product cost.

Is a sectional view showing a state of a shockless valve de-energized when the chair child is not moving. It is sectional drawing which shows the obstruction | occlusion state of a shockless valve. It is sectional drawing which shows the open state of a shockless valve. It is a hydraulic circuit of the first embodiment using the sheet Yokkuresu valve. It is a timing chart for demonstrating operation | movement of a hydraulic circuit same as the above. It is a hydraulic circuit which shows a 2nd Example.

Explanation of symbols

A Shockless valve G Oil reservoir G1 Upper oil reservoir G2 Lower oil reservoir 1 Coil 2 Stator 4 Housing 41 Lower housing 42 Upper housing 41b First flow channel 41c Second flow channel 41d Communication hole 41e port 41f port 41g Valve seat 5 Plunger 51 Large diameter part 52 Valve part

Claims (1)

In a hydraulic circuit in which a valve for supplying and discharging oil is connected to a hydraulic cylinder that moves up and down by hydraulic pressure,
A coil, a stator positioned and fixed inside the coil, an upper housing located in the coil, and an inflow and discharge of oil integrally formed with the upper housing at the respective hydraulic cylinder outflow inlets A housing composed of a lower housing in which first and second flow paths in which ports are formed are formed and a communication hole communicating with the upper housing is formed;
A plunger comprising a large diameter portion that moves through an inner peripheral surface of the upper housing and a gap and a valve portion that moves in the communication hole;
A spring that biases the plunger in a direction to release the plunger from the stator,
When the plunger is moved when the coil is energized, oil moves from the upper oil reservoir of the plunger to the lower oil reservoir of the plunger through the gap, and when the plunger is moved by the spring, the oil moves. a hydraulic circuit connecting a shockless valve plunger is moved slowly by the oil from the lower part oil sump to the upper portion oil sump through the clearance moves.

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