JP3611626B2 - hydraulic unit - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a hydraulic unit serving as a hydraulic source of a hydraulic actuator.
[0002]
[Prior art]
Japanese Patent Application No. 5-154124, filed by the present applicant, includes a hydraulic muffler in the supply path from the hydraulic pump to the hydraulic actuator. The hydraulic muffler has a vertical axis and protrudes upward from the tank. The hydraulic unit housed in is described. In general, the hydraulic unit is provided with a heater that heats the hydraulic oil in a low temperature state to raise the oil temperature so that the hydraulic oil in the tank does not become low temperature and hinder the smooth operation of the hydraulic actuator. When adjusting the oil temperature in such a tank, as described in Japanese Utility Model Publication No. 58-32002, a temperature detector such as a thermostat is used to detect the oil temperature. It is usually done inside.
[0003]
[Problems to be solved by the invention]
As described above, when the temperature detector is installed in the hydraulic fluid of the tank, the temperature detector is required to be oil resistant and expensive, and it is necessary to provide an insertion hole for the electric wire from the detector in the tank. There is also a problem that it takes time and effort to manufacture, and the hydraulic unit cannot be made inexpensive.
[0004]
The present invention is a hydraulic unit in which the hydraulic muffler protrudes out of the tank and is accommodated in the tank as described above. When the hydraulic oil in the tank is heated using the heater, the temperature detector is connected to the outside of the tank. It is intended to solve this problem by installing it in the above.
[0005]
[Means for Solving the Problems]
For this reason, in the present invention, a hydraulic muffler is provided in the supply path from the hydraulic pump to the hydraulic actuator, and the hydraulic muffler is configured by closing both ends of the cylindrical main body with end plates, and the upper end with the axis line in the vertical direction. The plate protrudes out of the tank and is housed in the tank. The upper end plate of the hydraulic muffler is transferred from the hydraulic oil through the hydraulic muffler body immersed in the hydraulic oil in the tank to reflect the oil temperature in the tank. A temperature detector that controls the energization of a heater that operates by detecting the temperature of the upper end plate and heats the hydraulic oil in the tank is installed on the upper end plate that exhibits this temperature .
[0006]
[Action]
According to such a configuration, the upper end plate of the hydraulic muffler protruding outside the tank is transferred from the hydraulic oil through the hydraulic muffler body immersed in the hydraulic oil in the tank, and the hydraulic oil in the tank The temperature reflects the oil temperature. Therefore, the temperature detector that operates by detecting this temperature energizes the heater so as to heat the hydraulic oil when the hydraulic oil temperature is too low, and the heater oil heats the hydraulic oil to a predetermined temperature. When the temperature rises over the range, the heater is energized and controlled so as to cut off the energization of the heater, and the oil temperature of the hydraulic oil in the tank can be suppressed from becoming lower than a predetermined value.
[0007]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
1 is a tank in which hydraulic oil is stored, and a hydraulic pump 2 and an electric motor 3 for driving the hydraulic pump 2 are integrally coupled on the upper plate 1A, and are placed and attached via a vibration isolating rubber 4. Has been. Reference numeral 5 denotes a suction pipe of the hydraulic pump 2, and a tip of the suction pipe is provided with a suction filter 6 and guided into the hydraulic oil in the tank 1. 7 is a discharge pipe of the hydraulic pump 2, and 8 is a control valve device connected to the discharge pipe 7.
[0008]
The control valve device 8 is connected to a return pipe 9 to the tank 1 and a supply / exhaust pipe 10, and the supply / exhaust pipe 10 is connected via a hydraulic muffler 11 to a hydraulic cylinder 12 that is a hydraulic actuator. 13 is connected. The hydraulic cylinder 12 is a single-acting type and drives an elevator (not shown). When the elevator is raised, the control valve device 8 shuts off the supply / discharge pipe 10 from the return pipe 9 and communicates it with the discharge pipe 7, and supplies the pressure oil from the hydraulic pump 2 to the supply / discharge pipe 10, the hydraulic muffler 11, The hydraulic cylinder 12 is supplied through the supply / discharge pipe 13 to advance the hydraulic cylinder 12, and when the elevator is lowered, the supply / discharge pipe 10 is disconnected from the discharge pipe 7 and connected to the return pipe 9. Is discharged to the return pipe 9 through the supply / discharge pipe 13, the hydraulic muffler 11, and the supply / discharge pipe 10, and the hydraulic cylinder 12 is moved backward by the load of the elevator.
[0009]
The hydraulic muffler 11 has a cylindrical main body 16 whose both ends are closed by end plates 14 and 15, and is arranged with its axis line in the vertical direction. The end plates 14 and 15 and the main body 16 are made of steel or the like. Made of metal. An inner chamber 17 is formed in the main body 16, and an upper end 18 is screwed into the end plate 14 to extend into the inner chamber 17, and is provided with an inlet / outlet 19 for the inner chamber 17. It is a cylinder. Reference numeral 20 denotes the other access hole provided in the end plate 14 for the inner chamber 18.
[0010]
On the end plate 14, a joint fitting 21 for connecting the supply / discharge pipe 10 to the access hole 19 and a joint fitting 22 for connecting the supply / discharge pipe 13 to the access hole 20 are welded. Reference numeral 23 denotes a through pipe welded to the end plates 14 and 15 so as to penetrate the hydraulic muffler 11 up and down, and is connected to the return pipe 9 at the upper end thereof. A series of return paths from the device 8 into the tank 1 is formed.
[0011]
The hydraulic muffler 11 is housed in a state in which the upper part protrudes from the tank 1 and is immersed in the hydraulic oil in the tank 1, and is placed on the upper plate 1 </ b> A of the tank 1 by the upper end plate 14 via the vibration isolating rubber 24. It is attached. By arranging the hydraulic muffler 11 in this way, the installation space for the hydraulic muffler 11 does not increase so much, and the hydraulic unit can be made compact. On the end plate 14 of the hydraulic muffler 11, a temperature detector 26 for controlling the energization of the sheet-like heater 25 attached to the outer surface of the front plate 1B of the tank 1 and a temperature protector 27 are attached ( (See FIG. 4).
[0012]
The end plate 14 of the hydraulic muffler 11 is transferred from the hydraulic oil through the main body 16 of the hydraulic muffler 11 through the hydraulic muffler 11 portion immersed in the hydraulic oil in the tank 1, and has a temperature reflecting the oil temperature in the tank 1. The temperature detector 26 and the temperature protector 27 are both formed by a thermostat that operates by detecting the temperature of the end plate 14 reflecting the oil temperature. The temperature detector 26 energizes the heater 25 to heat the hydraulic oil when the detected temperature is lower than the predetermined temperature, and interrupts the energization to the heater 25 when the detected temperature becomes somewhat higher than the predetermined temperature. The heater 25 is energized to adjust the oil temperature. Further, when the detected temperature is abnormally high, which is not normally acceptable, the temperature protector 27 cuts off all the connections with the power supply of the hydraulic unit such as the electric motor 3 and the heater 25, and stops the operation of the hydraulic unit. When this connection is interrupted, a kind of safety device is formed in which the connection with the power source is not resumed unless the temperature is sufficiently lowered, and a fire or the like is prevented.
[0013]
Reference numeral 28 denotes a cover that is formed by the frame 29, the front plate 30, and the rear plate 31 and covers devices on the upper plate 1 </ b> A of the tank 1. The frame 29 is formed of both side plates 29A and 29B and an upper plate 29C, and is attached to mounting pieces 32 provided on both sides of the upper plate 1A of the tank 1 by screw members 33 below the side plates 29A and 29B. The front plate 30 and the rear plate 31 are large enough to reach the lower part of the tank 1 from the upper plate 29C and close the front and rear of the frame 29. The frame 29 and the tank can be removed during maintenance work. 1 is attached by a screw member 34.
[0014]
Next, the operation of this embodiment will be described. When the hydraulic unit is connected to a power source and its operation is started, when the oil temperature of the hydraulic oil in the tank 1 is lower than a predetermined value, the temperature of the end plate 14 of the hydraulic muffler 11 reflecting this oil temperature is also lower than the predetermined value. The temperature detector 26 operates to energize the heater 25. As a result, the hydraulic oil in the tank 1 is heated by the heater 25 via the front plate 1B of the tank 1 and the oil temperature rises above a predetermined temperature, reflecting this, and the temperature of the end plate 14 of the hydraulic muffler 11 is reflected. Since the temperature rises beyond a predetermined value, the temperature detector 26 cuts off the power supply to the heater 25. Such an operation is repeated in response to a decrease in the oil temperature during the operation of the hydraulic unit, so that the oil temperature in the tank 1 is prevented from becoming lower than a predetermined temperature.
[0015]
When the elevator is raised, the electric motor 3 is driven and the control valve device 8 cuts off the supply / discharge pipe 10 from the return pipe 9 and communicates with the discharge pipe 7. After passing through the muffler 11, it is supplied to the hydraulic cylinder 12 to advance it. At this time, in the hydraulic muffler 11, the pressure oil from the supply / discharge pipe 10 flows into the inner chamber 17 from the inlet / outlet hole 19 and is expanded, and the pressure oil supplied to the hydraulic cylinder 12 is expanded by the expansion action of the inner chamber 17. Pulsation and vibration are attenuated, and the hydraulic unit and the elevator can be made quieter and the ride quality of the elevator can be improved.
[0016]
When the elevator is lowered, the electric motor 3 is stopped, and the control valve device 8 disconnects the supply / discharge pipe 10 from the discharge pipe 7 and communicates with the return pipe 9. As a result, the pressure oil from the hydraulic cylinder 12 passes through the hydraulic muffler 11 and is discharged into the tank 1 via the return pipe 9, and the hydraulic cylinder 12 moves backward under the load from the elevator. Also in this case, in the hydraulic muffler 11, the pressure oil from the supply / discharge pipe 13 flows into the inner chamber 17 through the inlet / outlet hole 20 and is expanded, and the pressure oil discharged from the hydraulic cylinder 12 by the expansion action by the inner chamber 17. Pulsation and vibration are attenuated, and the hydraulic unit and the elevator can be made quieter and the riding comfort of the elevator can be improved.
[0017]
When the temperature of the hydraulic oil in the tank 1 becomes abnormally high, the temperature protector 27 is activated by the temperature rise of the end plate 14 of the hydraulic muffler 11 reflecting this, and the connection between the hydraulic unit and the power source is cut off. The operation of the hydraulic unit is suspended.
[0018]
In such an operation, since the temperature detector 26 and the temperature protector 27 are attached to the end plate 14 of the hydraulic muffler 11 outside the tank 1, these temperature detectors are compared with the case where the temperature detector 26 and the temperature protector 27 are immersed in the hydraulic oil in the tank 1. 26 and the temperature protector 27 are not required to be oil-resistant and can be used inexpensively, and it is not necessary to provide a wire insertion hole for these in the tank 1, so it does not take time in the production of the tank 1, The hydraulic unit can be manufactured at low cost. The temperature detector 26 and the temperature protector 27 are installed by using the hydraulic muffler 11 itself originally provided in the hydraulic unit as a heat transfer medium from the hydraulic oil in the tank 1. Installation can be facilitated and installation space can be reduced as compared with the case where a medium is provided and used.
[0019]
【The invention's effect】
As described above, in the present invention, the hydraulic muffler is configured by closing both ends of the cylindrical main body with the end plates, and the upper end plate is protruded out of the tank with the axis extending vertically, and is accommodated in the tank. The end plate of the oil is transferred from the hydraulic oil through the main body of the hydraulic muffler immersed in the hydraulic oil in the tank and exhibits a temperature reflecting the oil temperature in the tank, and the upper end plate exhibiting this temperature A temperature detector is installed to control the energization of the heater that detects the temperature of the tank and heats the hydraulic oil in the tank. Since there is no need to provide a wire insertion hole for the detector, it is possible to manufacture the hydraulic unit at low cost without taking the trouble of manufacturing the tank.
[0020]
In addition, this temperature detector is installed on the upper end plate that protrudes outside the tank of the muffler by using the hydraulic muffler originally provided in the hydraulic unit as a heat transfer medium from the hydraulic oil in the tank. Compared with the case where the temperature detector is installed outside the tank with the heat medium installed, the installation space is small and can be installed easily.
[Brief description of the drawings]
FIG. 1 is a front view in which a part of an embodiment of the present invention is broken.
FIG. 2 is a right side view in which a part of an embodiment of the present invention is broken.
FIG. 3 is a cross-sectional view of a hydraulic muffler in one embodiment of the present invention.
FIG. 4 is an enlarged plan view of a main part in one embodiment of the present invention.
[Explanation of symbols]
1 Tank 2 Hydraulic Pump 11 Hydraulic Muffler 12 Hydraulic Actuator (Hydraulic Cylinder)
25 Heater 26 Temperature detector

Claims (1)

A hydraulic muffler is provided in the supply path from the hydraulic pump to the hydraulic actuator. This hydraulic muffler is constructed by closing both ends of the cylindrical main body with end plates, and the upper end plate protrudes out of the tank with the axis extending vertically. The upper end plate of the hydraulic muffler exhibits a temperature that is transferred from the hydraulic oil through the hydraulic muffler body immersed in the hydraulic oil in the tank and reflects the oil temperature in the tank. A hydraulic unit characterized in that a temperature detector for controlling energization of a heater that operates by detecting the temperature of the upper end plate and heats the hydraulic oil in the tank is installed on the upper end plate to be presented .

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