JP2008157027A - Electromagnetic pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic pump capable of largely saving the energy of a chucking or clamping circuit of a machine tool by the electromagnetic pump capable of being layered with a valve such as a directional control valve. <P>SOLUTION: In this electromagnetic pump 30, a pump part 32 is engaged with a solenoid valve 31. In the pump part 32, a body 48 is engaged with a stopper 38 by a screw mechanism, and a rod 43 of the stopper 38 is connected to one end of a piston member 49 slidingly fitted to and inserted into the body 48. The other end of the piston member 49 is pressed by a spring member 51 engaged with a piston shaft 52 installed in the body 48. A suction passage 56 and a delivery passage 57 are made to communicate with a pump room 54. A delivery check valve 62 is arranged in the middle of the delivery passage 57, and a suction check valve 60 is arranged in the middle of the suction passage 56. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electromagnetic pump, and more particularly to energy saving of an electromagnetic pump that can discharge liquid by operating an electromagnetic coil.

Conventionally, in a hydraulic device used for chucking or clamping in a machine tool or the like, the variable pump 5 is used. However, since the variable pump 5 and the electric motor 4 are always rotating at the time of clamping or in a standby state, Energy loss is large. In order to further save energy, the inverter 3 is attached to the electric motor 4 and the rotational speed of the electric motor 4 is controlled so that the wasteful flow rate is not discharged, and when the discharge flow rate is unnecessary, the rotational speed of the electric motor 4 is reduced. Energy saving is achieved (for example, refer to Patent Document 1).
JP2001-280257

However, in Patent Document 1, the rotation speed of the electric motor is controlled by an inverter to save energy. However, since the electric motor rotates at a low speed, energy loss occurs, and the pressure that is the actual work. Considering the replenishment of the circuit leak amount during holding and the input of the electric motor, the energy loss is large. In addition, the cost of inverters, controllers, drivers, etc. also becomes a problem.
Further, in Patent Document 1, there is one cylinder, but when a plurality of cylinders are used, pressure holding and control are complicated by a check valve or the like.
The present invention has been made in order to solve the above-described problems. An actuator is provided by integrating an electromagnetic coil and a pump main body having a pump mechanism for sucking and discharging a fluid, and attaching the pump main body to a valve that can be stacked. To provide an electromagnetic pump that can save energy by stopping the hydraulic pump (electric motor) when clamping and operating when the pressure drops. Objective.

In order to achieve the above object, the invention according to claim 1 is an electromagnetic valve member;
A pump member liquid-tightly engaged with the electromagnetic valve member;
The electromagnetic pump attached to the mounting plate can be laminated with a valve member.
According to the present invention, by stacking the valve member on the electromagnetic pump, the mounting space and the space space can be greatly reduced, and it is economical. Since the electromagnetic pump and the valve member are tightened with the stud bolt, the assembly time of the pipe is reduced, and the circuit can be assembled easily and quickly without requiring skill in the assembly work. Since centralized installation is possible, maintenance and inspection, and addition and modification of circuits are easy.
In the invention of claim 2, the pump member includes a suction passage provided in the pump body, a discharge passage provided in the pump body, a suction check valve provided in the middle of the suction passage, Since a discharge check valve provided in the middle of the discharge path is provided, the structure can be simplified and downsizing can be achieved.

According to a third aspect of the present invention, since the suction passage is sucked from the tank line of the stacked valves, there is no need for piping for the electromagnetic pump from the tank, which is preferable.
In the invention according to claim 4, since the discharge passage is connected to the pressure line of the stacked valves or the A or B line, it is not necessary to separately pipe the electromagnetic pump to the cylinder.
In the invention of claim 5, if the pump body is provided with a pressure adjusting mechanism, the maximum discharge pressure of the electromagnetic pump can be set, so that the pressure of the circuit does not rise above the set value, so that an abnormal force is applied to the clamping force. It ’s safe to join. In addition, a safety valve for setting the clamping force is unnecessary, and the cost can be reduced.

In the invention according to claim 6, when the electromagnetic pump is provided between one of the A and B lines and the tank line, it is not necessary to provide any special piping, and the hydraulic device can be made compact.
The invention according to claim 7 is suitable when the electromagnetic pump is provided in the middle of the pressure line because the pressure can be maintained in either the A line or the B line of the cylinder. The electromagnetic pump is also preferred because liquid can pass through the suction check valve and the discharge check valve even when not operating in the middle of the pressure line.
According to the eighth aspect of the present invention, since the fitting member sealing member between the pump main body and the piston member is mounted, the annular gap in the fitting portion between the main body and the piston member regardless of whether the electromagnetic coil is de-energized or excited. This is preferable because the internal leakage of the liquid from can be minimized.

  In the present invention, when using a clamp circuit, etc., a laminated type electromagnetic pump can be attached without attaching another pipe, and even if the drive of the motor is stopped during clamping, the clamping force is reduced due to leakage of the cylinder or valve. In this case, the clamping force can be maintained because the liquid is discharged from the electromagnetic pump by energizing the electromagnetic valve. Since the electromagnetic pump consumes electric power only when it is energized, it saves energy compared to when the electric motor is always driven.

The electromagnetic pump of the present invention will be described in detail below with reference to the drawings by giving preferred embodiments. FIG. 1 is a longitudinal sectional view showing a schematic structure of an electromagnetic pump 30 according to the first embodiment of the present invention.
As shown in FIG. 1, the electromagnetic pump 30 basically includes an electromagnetic valve (electromagnetic valve member) 31 that generates a suction force and a pump unit (pump member) 32.

  The electromagnetic valve 31 includes a coil body 33 including an electromagnetic coil 34 that generates a magnetic field, a coil case 35 that serves as an external magnetic path, and rings 36 and 37, and a stopper 38 that functions as a fixed core when a magnetic field is applied. A plunger 39 which is a movable iron core attracted by the motor, a guide 40 for supporting the plunger 39 and applying a magnetic field to the plunger 39, and a magnetic field flows from the guide 40 to the stopper 38 via the plunger 39. It is formed from the sleeve main body 42 provided with the welded nonmagnetic material 41. In this case, the electromagnetic coil 34 is attached to the coil case 35 and is inserted into the coil case 35 together with the rings 36 and 37 and inserted into a mold (not shown), and the coil body 33 is inserted by an injection molding machine. Molded.

A rod 43 formed integrally with the plunger 39 is inserted into the stopper 38 so as to be displaceable at an axial center thereof, and one end portion (left end in FIG. 1) of the rod 43 slides on the pump portion 32. It is in contact with the piston member 49 that is freely inserted.
When the coil main body 33 and the sleeve main body 42 are assembled, the sleeve 44 is inserted into the hole 33a of the coil main body 33, and the fixing nut 46 is screwed onto the screw portion 45a formed on the boss portion 45 of the sleeve 44. Has been. Further, the protruding portion 47 formed at one end portion (left end in FIG. 1) of the stopper 38 is joined to a screw mechanism 59a formed in the pump chamber 53 of the main body (pump main body) 48 of the pump portion 32.

  A piston member 49 is slidably fitted on the body 48 so as to be slidable on the same axis as the rod 43. One end (right end in FIG. 1) of the piston 49 member is at one end (left end in FIG. 1) of the rod 43. The other end (left end in FIG. 1) is in contact with the retainer 50 and is engaged with the piston shaft 52 via the spring member 51. The piston shaft 52 is movably provided in a screw mechanism (not shown) provided in a boss portion 55 screwed into a screw mechanism 59b in a pump chamber 54 opened in an end surface of the main body 48, and the piston shaft 52 is axially centered. When displaced in the direction, the elastic force of the spring member 51 is adjusted. Therefore, by adjusting the elastic force of the spring member 51, the attractive force by the excitation of the electromagnetic valve 31 acting on the piston member 49 is controlled, and the return force of the piston member 49 when the electromagnetic valve 31 is not excited is adjusted. Is done.

On the other hand, a suction passage 56 and a discharge passage 57 communicate with the pump chamber 54 so as to be formed in the main body 48 and substantially perpendicular to the axial direction. The suction path 56 communicates with a tank port 68 through which the return liquid of the valve passes through a suction check valve (pressure adjusting mechanism) 60, and the discharge path 57 is a liquid supply destination (not shown) A. Connected to port 66. Further, a discharge check valve (pressure adjusting mechanism) 62 is provided in the middle of the discharge path 57. The discharge check valve 62 opens when the liquid flows from the pump chamber 54 to the discharge passage 57 and closes when the liquid flows from the suction passage 56 to the pump chamber 54. Here, a pump mechanism 63 is formed by the pump chamber 54, the suction path 56, the discharge path 57, the suction check valve 60, and the discharge check valve 62.
The main body 48 is connected with a flow path 64 communicating with the pump chamber 53 and the tank port 68. The flow path 64 has a function of causing the liquid stored in the pump chamber 53 to flow into the tank port 68 when the piston member 49 is displaced in the direction of the arrow X or Y, and reducing the pressure of the liquid in the pump chamber 53.
Reference numeral 65 indicates a pressure port connected to a pressure supply source (not shown), and reference numeral 67 indicates a B port communicating with a liquid supply destination. The attachment hole 69 formed in the main body 48 is for attaching the electromagnetic pump 30 to the sub plate 74 (see FIG. 3).

The electromagnetic pump 30 according to the first embodiment of the present invention is basically configured as described above, and the operation of the electromagnetic pump 30 will be described with reference to FIG.
FIG. 2A shows a state where the electromagnetic coil 34 is not excited (OFF). In this state, the piston member 49 is displaced in the arrow X direction via the retainer 50 by the elastic force of the spring member 51. Therefore, the rod 43 is displaced in the arrow X direction together with the plunger 39. At that time, the pump chamber 54 is in a negative pressure state because the piston member 49 is displaced and drawn in the direction of the arrow X, so that the liquid filled in the tank port 68 enters the suction path 56 via the suction check valve 60. The pump chamber 54 is sucked and filled.

  Next, as shown in FIG. 2B, when the electromagnetic coil 34 is energized (ON), the plunger 39 is displaced in the direction of the arrow Y because it is attracted to the stopper 38. Therefore, the piston member 49 is pressed by the rod 43 and the spring member 51 is bent in the arrow Y direction by the retainer 50. As a result, when the piston member 49 starts to move, the pump chamber 54 is pressurized with the liquid in the pump chamber 54, and the discharge check valve 62 is opened by the liquid. It is discharged from the passage 57 to the A port 66. When the piston member 49 starts moving in the arrow Y direction, the pump chamber 53 communicates with the tank port 68 through the flow path 64, so that an increase in the back pressure of the pump chamber 53 is avoided.

FIG. 2C shows a state where the excitation of the electromagnetic coil 34 is completed. In this state, the plunger 39 is attracted by the stopper 38, and the rod 43 deflects the spring member 51 in the arrow Y direction via the piston member 49, and the suction force of the electromagnetic coil 34, the elastic force of the spring member 51, and the pump chamber 54. The force acting on the piston member 49 due to this pressure is ensured in equilibrium.
When the electromagnetic coil 34 is de-energized, the plunger 39 is displaced in the arrow X direction. Therefore, the piston member 49 cooperates with the rod 43 by the elastic force of the spring member 51. As a result, the pump chamber 54 becomes negative pressure, and the pump chamber 54 is filled with liquid from the tank port 68 via the suction check valve 60 communicating with the suction passage 56.

  FIG. 3 shows an electromagnetic pump 30 (see FIG. 1), a direction switching valve (valve member) 72 that switches the operating direction of the cylinder 75 (see FIG. 4), and a pilot check valve (valve member) that holds the pressure of the cylinder 75. 73) are external views of the laminated valve 70 which is stacked and attached to the sub-plate 74 by a screw member (not shown), (A) is a front view, and (B) is a side view.

  FIG. 4 shows a hydraulic circuit diagram 80 in which the workpiece 76 is clamped and unclamped by the cylinder 75 using the laminated valve 70, and the pressure fluid is switched by the pump (not shown) of the pressure source 77. The state where the workpiece 76 is clamped by the cylinder 75 is shown. At this time, the electromagnetic pump 30 is provided between the A port of the directional switching valve 72 and the tank port T. The directional switching valve 72 is in a neutral position, and the A port and B port of the cylinder 75 communicate with the tank port T. . In this case, the electromagnetic pump 30 may of course be provided between the B port and the tank port T.

  Therefore, when the pump of the pressure source 77 is stopped in a state where the workpiece 76 is clamped by the cylinder 75, the clamping force is reduced due to leakage of the pressure fluid from the cylinder 75 or the pilot check valve 73. At this time, the pressure drop due to the leakage of the pressure fluid is detected by the pressure sensor 78, the electromagnetic pump 30 is energized, and the pressure liquid enters the A port 66 by the excitation operation of the electromagnetic pump 30, and the pressure of the pressure fluid increases. The clamp of the workpiece 76 is held.

  If the leak amount of the cylinder 75 or the pilot check valve 73 is clear, the pressure sensor 78 is unnecessary, and the pressure can be maintained by energizing the electromagnetic pump 30 periodically. At that time, as described above, the pressure of the electromagnetic pump 30 is the force generated by the attraction force of the electromagnetic coil 34 (see FIG. 1) and the elastic force of the spring member 51 (see FIG. 1) and the pressure applied to the area of the piston member 49. When the elastic force of the spring member 51 is set so as to balance, when the pressure is increased by energization, the plunger 39 is not attracted to the stopper 38 and the discharge pressure does not increase abnormally.

FIG. 5 is a time chart showing an operation state of the hydraulic circuit diagram of FIG. In FIG. 5A, a waveform 5A indicates the correlation between the time from when the clamping force is applied to the workpiece 76 by the cylinder 75 to the release and the clamping pressure, and the waveforms 5B1 to 5B3 shown in FIG. These show the displacement state in the time passage of the power consumption of the electromagnetic pump 30 in the state of the waveform 5A.
Furthermore, waveforms 5C1 and 5C2 shown in FIG. 5C show the displacement state of the rotational speed of the electric motor (not shown) of the pressure source 77 in the state of the waveform 5A over time, and the waveforms 5D1 and 5C in FIG. 5D2 shows the displacement state over time of the power consumption of the motor in the state of waveform 5A.

As shown in FIG. 5C, when the motor of the pressure source 77 rotates at a predetermined number of revolutions for a predetermined time with the waveform 5C1, the pressure fluid from the pressure source 77 causes the direction switching valve 72 and the pilot check valve 73 to rotate. Thus, a clamping pressure like a waveform 5A is applied to the workpiece 76 as shown in FIG.
In the present invention, the electric power consumption of the electric motor rises until it reaches a predetermined maximum rotational speed after passing through a predetermined rotational speed for a certain time immediately after starting, as indicated by a waveform 5D1 in FIG. After a predetermined maximum number of revolutions has elapsed, the motor starts to descend, and after a predetermined number of revolutions have passed for a certain period of time, the motor is stopped. In a normal circuit, when the motor is stopped, the waveform 5A in FIG. 5A continues to descend to the right, and the clamp pressure decreases, so the motor cannot be stopped. When the clamp is removed, the electric power consumption waveform 5D2 shown in FIG. 5D is substantially the same as the waveform 5D1.

  In FIG. 5A, when the clamp pressure is held in the state of the waveform 5A, the clamp pressure lowering point with the passage of time in the waveform 5A due to leakage of pressure fluid from the cylinder 75 or the pilot check valve 73 in the middle of the hold state. 5A1 to 5A3 are generated. Therefore, when the pressure values at the clamp pressure lowering points 5A1 to 5A3 are detected by the pressure sensor 78 and the electromagnetic pump 30 is energized and pressure liquid is supplied by the excitation operation of the electromagnetic pump 30, the pressure of the pressure fluid increases. The clamp of the workpiece 76 is held. At this time, as shown in FIG. 5B, the power consumption of the electromagnetic pump 30 is as shown by the waveforms 5B1 to 5B3, and the energization time of the electromagnetic pump 30 is as short as about 50 ms, for example, so the power consumption is very small.

  FIG. 6 shows a hydraulic circuit diagram in which the pilot check valve 73 of FIG. 4 is not provided. For example, by supplying a flow rate of pressurized fluid that exceeds the leakage amount of the direction switching valve 72, the direction switching valve 72 is in an all-port position in the neutral position. The pilot check valve 73 is not necessary when maintaining the block state.

FIG. 7 shows a modification of FIG. 4, showing a hydraulic circuit diagram 80 in which the workpiece 76 is clamped and unclamped by the cylinder 75 using the laminated valve 70, and the pressure fluid is pumped by a pump (not shown) of the pressure source 77. A state in which the workpiece 76 is clamped by the cylinder 75 by the switching operation of the direction switching valve 72 is shown. At this time, the electromagnetic pump 30 is provided in the middle of a pipe line (not shown) that communicates the pressure source 77 and the pressure port P of the direction switching valve 72. The direction switching valve 72 is in the neutral position at the A port and B of the cylinder 75. The port communicates with the tank port T.
FIG. 8 shows a modification of FIG. 6 in which the electromagnetic pump 30 is provided in the middle of a conduit (not shown) that connects the pressure source 77 and the pressure port P of the direction switching valve 72.

  9 to 11 show a schematic structure of an electromagnetic pump 90 according to the second embodiment actually designed. 9 to 11, the same components as those of FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 12 shows a schematic structure of an electromagnetic pump 100 according to the third embodiment of the present invention. In FIG. 12, the same components as those of FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. The same shall apply hereinafter.
In FIG. 12, the electromagnetic pump 100 is characterized in that a seal member 102 is provided between a main body 48 and a piston member 49 slidably inserted into the main body 48 to improve the efficiency of the electromagnetic pump 100.
That is, by attaching a seal member, for example, an O-ring 102, to the annular groove 101 formed in the outer peripheral portion of the piston member 49 slidably inserted into the main body 48 in FIG. Regardless of this, it is possible to minimize the internal leakage of the liquid from the annular gap in the fitting portion between the main body 48 and the piston member 49. Of course, a low-sliding seal member such as a cap seal may be provided in place of the O-ring 102.
FIG. 13 shows a schematic structure of an electromagnetic pump 110 according to the fourth embodiment of the present invention. In FIG. 13, the seal member 102 is attached to an annular groove 111 formed in the main body 48.

It is a longitudinal section showing a schematic structure of an electromagnetic pump concerning a first embodiment of the present invention. It is operation | movement explanatory drawing of the electromagnetic pump of FIG. (A) is the front view which attached the electromagnetic pump of FIG. 1 to the subplate, and was made into the laminated valve, (B) is the side view of (A). It is a hydraulic circuit diagram which operates a cylinder using the laminated valve of FIG. It is a time chart figure of the hydraulic circuit using the electromagnetic pump of FIG. It is another hydraulic circuit diagram which operates a cylinder using the laminated valve of FIG. FIG. 5 is a hydraulic circuit diagram of a modified example of FIG. 4. It is a hydraulic circuit diagram of the modification of FIG. It is a longitudinal cross-sectional view of the actually designed electromagnetic pump. FIG. 10 is a longitudinal sectional view of FIG. 9. It is sectional drawing of the XI-XI arrow of FIG. It is a longitudinal cross-sectional view which shows schematic structure of the electromagnetic pump which concerns on 3rd embodiment of this invention. It is a longitudinal cross-sectional view which shows schematic structure of the electromagnetic pump which concerns on 4th embodiment of this invention.

Explanation of symbols

30, 90, 100, 110 Electromagnetic pump
31 Solenoid valve 32 Pump part 34 Electromagnetic coil 48 Main body 56 Suction path 57 Discharge path 60 Discharge check valve 62 Suction check valve 65 Pressure port 66 A port 67 B port 68 Tank port 70 Laminated valve 80, 81 Hydraulic circuit diagram 101, 111 annular groove 102 seal member

Claims (8)

A solenoid valve member;
A pump member liquid-tightly engaged with the electromagnetic valve member;
In an electromagnetic pump with
The electromagnetic pump attached to a mounting plate can be laminated with a valve member. The electromagnetic pump according to claim 1,
The pump member is
A suction passage provided in the pump body;
A discharge passage provided in the pump body;
A suction check valve provided in the middle of the suction path;
A discharge check valve provided in the middle of the discharge path;
An electromagnetic pump comprising: The electromagnetic pump according to claim 1 or 2,
The electromagnetic pump according to claim 1, wherein the suction path is installed in a return line of stacked valves. The electromagnetic pump according to any one of claims 1 to 3,
The electromagnetic pump according to claim 1, wherein the discharge path is connected to a pressure line of a stacked valve or an A or B line. The electromagnetic pump according to any one of claims 1 to 4,
An electromagnetic pump characterized in that a pressure adjusting mechanism is provided in the pump body.   5. The electromagnetic pump according to claim 1, wherein the electromagnetic pump is provided between one of the A and B lines and a tank line. 6.   5. The electromagnetic pump according to claim 1, wherein the electromagnetic pump is provided in the middle of a pressure line. The electromagnetic pump according to any one of claims 1 to 7,
A pump member, wherein a fitting portion seal member between the pump main body and the piston member is mounted.

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