JP4809949B2 - Hydraulic device - Google Patents

Description

  The present invention relates to a hydraulic apparatus that supplies hydraulic oil to an actuator.

This type of hydraulic device (hydraulic power source) includes a pump, an electric motor, a tank, and the like, and a pressure increasing cylinder is branched and connected to a line connecting the hydraulic device and a clamp cylinder as an actuator. When the workpiece is clamped by the clamp cylinder, the hydraulic oil increased in pressure is supplied from the pressure increasing cylinder to the clamp cylinder, and clamping is performed only by the hydraulic oil from the pressure increasing cylinder, and hydraulic oil is supplied from the hydraulic source. Since it is not necessary, the hydraulic power source can be stopped to save energy.
JP 2002-174201 A

  However, in such a conventional hydraulic apparatus, if there is a leak from the clamp cylinder or the booster cylinder during clamping, the volume of the pressurization chamber of the booster cylinder becomes almost zero immediately. There was a problem that the hydraulic oil to be supplied was lost and satisfactory clamping was not possible.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a hydraulic device that can satisfactorily prevent the operating oil supplied from the pressure increasing cylinder to the actuator from being lost, while saving energy without constantly rotating the electric motor that rotates the pump. It is.

In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
A tank that stores hydraulic oil inside, an electric motor that rotationally drives the pump, a pump that is rotationally driven by the electric motor to suck and discharge the stored hydraulic oil in the tank, and the internal hydraulic oil is increased by the action of compressed air The booster cylinder is composed of a large cylinder part and a small cylinder part with a smaller diameter than that of the large cylinder part and filled with hydraulic oil inside. A piston with compressed air acting on one side is slidably inserted, and the piston is provided with a piston rod that protrudes from the other side opposite to the one side. The piston rod is provided with its tip extending inside the small cylinder. The pressure-increasing cylinder includes a first detecting means for detecting that the piston rod has moved to one set position as the hydraulic oil filled in the small cylinder portion decreases, and for generating a detection signal. It provided a second detection means for issuing a detection signal by detecting that the piston rod with for hydraulic oil is filled in the small cylinder portion is moved to the other set position, the electric motor and the two sensing means electrically connected supplies the hydraulic oil discharged from the first pump to energize the motor to rotate driving the pump by the detection signal from the detection means into the small cylinder portion, the electric motor by the detection signal from the second sensing means non This is a hydraulic device including a control panel that is energized and stopped.

As described above in detail, according to the first aspect of the present invention, the hydraulic oil discharged from the small cylinder portion of the pressure increasing cylinder is supplied to the actuator, and the hydraulic oil supplied to the actuator is filled in the small cylinder portion. When the first detecting means detects that the oil has decreased and the piston rod has moved to one of the set positions as the hydraulic oil has decreased, and the detection signal is generated, the control panel uses the detection signal to energize the motor. Then, the pump is driven to rotate and the hydraulic oil discharged from the pump is supplied into the small cylinder. Then, when the second detecting means detects that the piston rod has moved to the other set position as the small cylinder portion is filled with the hydraulic oil and generates a detection signal, the control panel causes the electric motor to be turned on by this detection signal. Deenergized and stopped. For this reason, the piston rod moves to one set position, the first detection means emits a detection signal to energize the motor to drive the pump to rotate, and the piston rod moves to the other set position to move to the second position. Since the detection means generates a detection signal and stops the electric motor by de-energizing it , the pump is driven to rotate by the electric motor until the piston rod moves from one set position to the other set position. There is a detection signal generated from the first detection means when the hydraulic oil charged in the small cylinder portion of the pressure increasing cylinder is reduced while energy saving can be achieved without always rotating the electric motor that rotates the pump. Thus, since the pump is driven to rotate and the hydraulic oil is filled in the small cylinder portion, it is possible to satisfactorily prevent the hydraulic oil supplied from the pressure increasing cylinder to the actuator from being lost.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1 to FIG. 4, reference numeral 1 denotes a tank for storing hydraulic oil therein, and the upper and lower openings of the cylindrical member 2 are closed by thick plate-like upper flange members 3 and lower flange members 4. The tubular member 2 is sandwiched between them and fixed with four tie rods 5. Reference numeral 6 denotes an electric motor that rotationally drives the pump 7, which is mounted on the front surface 3A of the upper flange member 3 with the drive shaft 6A facing downward, and the drive shaft 6A is disposed between the front surface 3A and the rear surface 3B of the upper flange member 3. It is housed in the through-hole 8 provided through. The pump 7 is attached to the back surface 3B of the upper flange member 3 with the rotary shaft 7A facing upward, and the rotary shaft 7A is received in the through hole 8 and coupled to the drive shaft 6A of the electric motor 6. 1 storage hydraulic oil is sucked and discharged. Reference numeral 9 denotes a suction pipe of the pump 7, which hangs down from the pump 7 and has its tip immersed in hydraulic oil. Reference numeral 10 denotes a first discharge passage through which hydraulic oil discharged from the pump 7 flows. The upper flange member 3 is perforated so that one end is opened on one side surface 3C of the upper flange member 3 and the other end is formed on the upper flange member 3. It is connected to a discharge port that opens on the back surface 3B and opens on the top surface of the pump 7. 11 is a return flow path through which hydraulic oil flowing back from the actuator (not shown) flows into the tank 1, with one end opened on one side 3C of the upper flange member 3 and the other end opened on the back surface 3B of the upper flange member 3; The return pipe 12 is connected to the other end opened to the back surface 3B, and the return pipe 12 is suspended from the back surface 3B of the upper flange member 3 and the tip is immersed in the stored hydraulic oil.

  13 is a safety valve for setting the upper limit of the pressure of the hydraulic oil discharged from the pump 7, which is attached to the two side surfaces 3D orthogonal to the one side surface 3C of the upper flange member 3, and is connected to the first discharge channel 10 via the connection channel 14. When the pressure of the hydraulic oil that is connected and discharged from the pump 7 exceeds the set value, the hydraulic oil is opened, and the hydraulic oil flows through the discharge pipe 15 that hangs down from the back surface 3B of the upper flange member 3 to return to the inside of the tank 1. A pressure gauge 16 displays the pressure of the hydraulic oil discharged from the pump 7 and is attached to the two side surfaces 3D of the upper flange member 3 and connected to the first discharge flow path 10. Reference numeral 17 denotes a check valve that prevents the reverse flow of hydraulic oil discharged from the pump 7, and is provided in the first discharge flow path 10 and provided inside the upper flange member 3. 18 is an oil filler / air breather attached to the two side surfaces 3D of the upper flange member 3, and 19 is an oil level gauge that makes it possible to visually recognize the amount of stored hydraulic oil in the tank 1 from the outside.

  Reference numeral 50 denotes a pressure-increasing cylinder that boosts and discharges the internal hydraulic oil by the action of compressed air. Are combined. The large cylinder portion 51 is configured by fixing a thick plate-like lower flange member 55 with four tie rods 56 via a large-diameter large cylindrical member 54 below the flange member 53. The small cylinder portion 52 is configured by fixing a thick plate-like upper flange member 58 with four tie rods 59 via a small tubular member 57 having a diameter smaller than that of the large tubular member 54 above the flange member 53 and operating inside. Filled with oil. The pressure increasing cylinder 50 abuts one side surface 53 </ b> A of the flange member 53 with one side surface 3 </ b> C of the upper flange member 3 constituting the tank 1. Then, four bolt members 60 (two are shown in FIG. 3 in the horizontal direction from the other side 53B opposite to one side 53A of the flange member and the other two are below the two shown. ) Is inserted into the upper flange member 3 of the tank 1 and the tank 1 and the pressure increasing cylinder 50 are detachably coupled. Further, the lower flange member 4 of the tank 1 and the lower flange member 55 of the pressure-increasing cylinder 50 abut against each other, and are coupled via an L-shaped metal fitting 61.

  62 is a piston that is slidably inserted into the large cylinder portion 51, and the inside of the large cylinder portion 51 is partitioned into an upper chamber 51A and a lower chamber 51B, and the upper chamber 51A extends through the flange member 53. While opening to air | atmosphere via the opening hole 51C, compressed air is always introduce | transduced into the lower chamber 51B. In the piston 62, the compressed air introduced into the lower chamber 51B always acts on the lower surface as one surface. A piston rod 63 protrudes from the upper surface opposite to the lower surface on which the compressed air of the piston 61 acts. The piston rod penetrates the flange member 53 and extends into the small cylinder portion 52, and a magnet 64 is provided at the tip. Yes. Reference numeral 65 denotes a second discharge flow channel connected to the first discharge flow channel 10, and one end is connected to the inside of the small cylinder portion 52 and the other end is formed in the flange member 53 so as to open to one side surface 53A. . Reference numeral 66 denotes a third discharge flow path that branches and connects to the second discharge flow path 65. The first discharge flow path is formed in the flange member 53 and has one end opened on the surface of the flange member 53, and this opening is connected to the actuator side (not shown). The connection port 66A is used. 67 is a second return flow path connected to the return flow path 11 and has one end opened on the surface of the flange member 53 and the other end opened in the side surface 53A so as to open to the surface. Are connected to the actuator side as a second connection port 67A. Reference numeral 68 denotes a connection flow path that connects the third discharge flow path 66 and the second return flow path 67 and is formed in the flange member 53.

  Reference numeral 69 denotes a first solenoid valve disposed in the third discharge flow channel 66. The third discharge flow channel 66 is normally opened without being energized, and energized when it is not necessary to supply hydraulic oil from the pressure increasing cylinder 50 to the actuator. Thus, the third discharge flow channel 66 is blocked. Reference numeral 70 denotes a second solenoid valve disposed in the connection flow path 68. The connection flow path 68 is normally shut off by energization, and the connection flow path 68 is de-energized when the entire power supply is turned off or during an emergency stop. I try to open it. The electromagnetic valves 69 and 70 are attached to two side surfaces 53C orthogonal to the one side surface 53A and the other side surface 53B of the flange member 53. 71A is a first detecting means attached to the upper portion of the tie rod 59 of the small cylinder portion 52 constituting the pressure increasing cylinder 50. The first detecting means is composed of a proximity position detection switch, and the hydraulic oil filled in the small cylinder portion 52 is supplied to the actuator. When the piston rod 63 moves upward and reaches one set position (indicated by a two-dot chain line in FIG. 1), the magnet 64 provided at the tip of the piston rod 63 approaches. A detection signal is generated by the above. 71B is a second detection means attached to the lower part of the tie rod 59, and is composed of a proximity position detection switch like the first detection means 71A. The hydraulic oil discharged from the pump 7 is filled in the small cylinder portion 52. Accordingly, when the piston rod 63 moves downward and reaches the other set position (indicated by a solid line in FIG. 1) where the inside of the small cylinder portion 52 is filled with hydraulic oil, a detection signal is generated due to the approach of the magnet 64. It is something that is emitted. Reference numeral 20 denotes a control panel fixed to the three side surfaces 3E orthogonal to the one side surface 3C of the upper flange member 3 and opposed to the two side surfaces 3D, and electrically connects the electric motor 6 and both detection means 71A, 71B to the first detection means. The electric motor 6 is energized by the command signal from 71A to rotate the pump 7, and the hydraulic oil discharged from the pump 7 flows through the first discharge passage 10 and the second discharge passage 65 into the small cylinder portion 52. In addition to being charged, the motor 6 is de-energized and stopped by a command signal from the second detection means 71B.

Next, the operation of this configuration will be described.
The first connection port 66A and the second connection port 67A are each connected to an actuator via an electromagnetic switching valve (not shown). At this time, the connection ports 66A and 67A and the actuator are blocked by the electromagnetic switching valve. Then, the second electromagnetic valve 70 is energized to block the connection flow path 68.

  In this state, when the pump 7 is rotationally driven by the electric motor 6, the pump 7 sucks the hydraulic oil stored in the tank 1 from the suction pipe 9 and discharges it to the first discharge flow path 10. 2 flows through the discharge passage 65 and is supplied to the inside of the small cylinder portion 52 of the pressure increasing cylinder 50. The piston 62 and the piston rod 63 of the pressure increasing cylinder 50 are moved downward against the acting force based on the pressure of the compressed air acting on the lower surface of the piston 62 by the acting force based on the pressure of the hydraulic oil supplied to the small cylinder portion 52. When the piston rod 63 reaches the other set position where the hydraulic oil is filled in the small cylinder portion 52, the other detection means 71B issues a detection signal and stops the electric motor 6.

  Then, when the electromagnetic switching valve (not shown) is operated to switch between the connection ports 66A, 67A and the actuator, the pressure increasing cylinder 50 is applied with an acting force based on the pressure of the compressed air acting on the lower surface of the piston 62. The piston 62 and the piston rod 63 are moved upward, and the hydraulic oil filled in the small cylinder portion 52 is increased in pressure based on the area ratio between the piston 62 and the piston rod 63 and discharged. The discharged hydraulic oil flows from the second discharge flow path 65 through the third discharge flow path 66, the first electromagnetic valve 69, and the first connection port 66A, and is supplied to the actuator. The hydraulic oil from the actuator is supplied to the second connection port. 67A flows through the second return flow path 67, the return flow path 11 and the return pipe 12 and is returned to the inside of the tank 1. At this time, the hydraulic oil discharged to the second discharge passage 65 is blocked from flowing toward the pump 7 by the check valve 17.

  When the hydraulic oil filled in the small cylinder portion 52 is reduced by the supply of hydraulic oil to the actuator and the piston rod 63 moving upward reaches one set position, one detection means 71A issues a detection signal. Then, the pump 7 is rotationally driven again by the electric motor 6, and the hydraulic oil discharged from the pump 7 is supplied into the small cylinder portion 52. With this supply, when the small cylinder portion 52 is filled with hydraulic oil and the piston rod 63 reaches the other set position, the other detection means 71B issues a detection signal and stops the electric motor 6.

  When the actuator is stopped for a long time, such as when it is stopped until the next work is started after the work by the actuator is completed, the first discharge valve 66 is shut off by energizing the first electromagnetic valve 69. The leakage of hydraulic oil filled in the small cylinder portion 52 is prevented. Further, at the time of emergency stop, the electric motor 6 is stopped, the second electromagnetic valve 70 is de-energized to open the connection flow path 68, and the hydraulic oil filled in the small cylinder portion 52 is secondly supplied from the connection flow path 68. The return flow path 67, the return flow path 11, and the return pipe 12 flow to return to the inside of the tank 1.

  With this operation, the piston rod 63 of the pressure increasing cylinder 50 moves to one setting position, the first detection means 71A generates a detection signal, and the pump 7 is driven to rotate by the electric motor 6, and the piston rod 63 is set to the other setting position. Moving to the position, the second detection means 71B issues a detection signal and stops the electric motor 6. For this reason, the motor 7 rotates the pump 7 because the piston rod 63 of the pressure-increasing cylinder 50 moves from one set position to the other set position. The detection signal generated from the first detection means 71A as the hydraulic oil charged in the small cylinder portion 52 of the pressure-increasing cylinder 50 is reduced while energy saving can be achieved without always driving the motor 6 to be driven. Thus, since the pump 7 is rotationally driven to fill the small cylinder portion 52 with the hydraulic oil, it is possible to satisfactorily prevent the hydraulic oil supplied from the pressure-increasing cylinder 50 to the actuator. In addition, since the electric motor 6 can be intermittently driven without always rotating, the noise can be reduced and the temperature rise of the hydraulic oil can be satisfactorily suppressed. The pump 7 may be a small pump that fills the small cylinder portion 52 of the booster cylinder 50 with hydraulic oil, and the electric motor 6 that rotationally drives the small pump 7 can be small.

  Further, the upper flange member 3 of the tank 1 having the electric motor 6 attached to the front surface 3A and the pump 7 attached to the rear surface 3B and the flange member 53 of the pressure increasing cylinder 50 are brought into contact with each other on the side surfaces 3C and 53A. 1 and the pressure increasing cylinder 53 are detachably coupled by a bolt member 60. The upper flange member 3 of the tank 1 is provided with a first discharge flow path 10 through which hydraulic oil discharged from the pump 7 flows and a return flow path 11 through which hydraulic oil flowing back from the actuator into the tank 1 flows. . Further, the flange member 53 of the pressure increasing cylinder 50 is provided with a second discharge passage 65 having one end connected to the inside of the small cylinder portion 52 and the other end connected to the first discharge passage 10. Further, the flange member 53 is provided with a third discharge channel 66 that is branched and connected to the second discharge channel 65 and connected to the actuator side. For this reason, it is possible to connect the pump 7, the tank 1, and the pressure increasing cylinder 50 without external piping, and the pump 7, the electric motor 6, the tank 1, and the pressure increasing cylinder 50 can be integrated to make the entire apparatus compact. can do.

  Further, since the compressed air is always applied to the lower surface of the piston 62 of the pressure increasing cylinder 50 and hydraulic oil discharged from the pump 7 is supplied against the pressure of the compressed air, the small cylinder portion 52 is supplied. Due to the reduction of the hydraulic oil filled in the hydraulic oil, the hydraulic oil can be supplied to the actuator even when the hydraulic oil is supplied from the pump 7 into the small cylinder portion 52, and the hydraulic oil is always supplied satisfactorily to the actuator. be able to.

  In one embodiment, the third discharge flow path 66 connected to the actuator side is branched and connected to the second discharge flow path 65 and drilled in the flange member 53 of the pressure increasing cylinder 50. The upper flange member of the tank may be formed by branch connection to the first discharge flow path. In addition, the flange member 53 has a second return channel 67 connected to the return channel 10 and connected to the actuator side. However, the return channel is directly connected to the actuator side without providing the second return channel. May be. Furthermore, although the connection ports 66A and 67A that open to the surface of the flange member 53 are directly connected to the actuator side, they are connected to the connection port and a manifold is erected on the surface of the flange member. An electromagnetic switching valve that controls the flow rate, a flow rate control valve that controls the flow rate of hydraulic oil, a pressure control valve that controls the pressure of hydraulic fluid, a pressure switch that detects the pressure of hydraulic fluid, etc. are optionally attached, and from this manifold to the actuator side Of course, they may be connected.

1 is a front view of a hydraulic apparatus partially shown in cross section in an embodiment of the present invention. It is a hydraulic circuit diagram of one embodiment. It is sectional drawing along line AA of FIG. It is a top view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Tank 6: Electric motor 7: Pump 50: Boosting cylinder 51: Large cylinder part 52: Small cylinder part 62: Piston 63: Piston rod 71A: 1st detection means 71B: 2nd detection means

Claims (1)

A tank that stores hydraulic oil inside, an electric motor that rotationally drives the pump, a pump that is rotationally driven by the electric motor to suck and discharge the stored hydraulic oil in the tank, and the internal hydraulic oil is increased by the action of compressed air The booster cylinder is composed of a large cylinder part and a small cylinder part with a smaller diameter than that of the large cylinder part and filled with hydraulic oil inside. A piston with compressed air acting on one side is slidably inserted, and the piston is provided with a piston rod that protrudes from the other side opposite to the one side. The piston rod is provided with its tip extending inside the small cylinder. The pressure-increasing cylinder includes a first detecting means for detecting that the piston rod has moved to one set position as the hydraulic oil filled in the small cylinder portion decreases, and for generating a detection signal. It provided a second detection means for issuing a detection signal by detecting that the piston rod with for hydraulic oil is filled in the small cylinder portion is moved to the other set position, the electric motor and the two sensing means electrically connected supplies the hydraulic oil discharged from the first pump to energize the motor to rotate driving the pump by the detection signal from the detection means into the small cylinder portion, the electric motor by the detection signal from the second sensing means non A hydraulic apparatus comprising a control panel that is energized and stopped.

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