JPS6217407A - Oil temperature control device in accumulator circuit - Google Patents

Abstract

PURPOSE:To avoid unstable operation of an actuator due to a low oil temperature by forcedly circulating a working fluid through a relief valve by a controller. CONSTITUTION:A temperature sensor 12 is provided on a tank 1, and an output of the temperature sensor 12 is input to a controller 11. When it is judged by the controller 11 that oil temperature is less than a designated value, accord ing to a command signal from the controller 1, the operation of a hydraulic pump 2 is continued to circulate a working fluid through a relief valve 7. Thus, a low oil temperature can be raised up to a moderate temperature in a short time, so that unstable operation of an actuator due to low oil temperature can be eliminated quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for obtaining an appropriate oil temperature in an accumulator circuit.

[Prior Art 1] Various types of accumulator circuits have been developed in the past, and the one shown in FIG. 5 is one of the typical configurations. The illustrated accumulator circuit accumulates hydraulic oil sucked up from a tank 1 by a hydraulic pump 2 in an accumulator 3, and controls the first solenoid pulp 4 to use the accumulated hydraulic oil for hydraulic silling, etc. feed into actuator 5,
The actuator 5 is configured to operate rapidly, and hydraulic oil is returned from the actuator 5 to the tank 1 via a second solenoid valve 6. A relief valve 7 is provided between the hydraulic pump 2 and the accumulator 3, and when the pressure in the circuit exceeds a predetermined value, the relief valve 7 opens to return hydraulic oil to the tank 1. It has become. Furthermore, in the illustrated accumulator circuit, a pressure sensor 8 is attached to the accumulator 3, and when the pressure inside the accumulator 3 reaches a predetermined value, the electric motor 9 driving the hydraulic pump 2 is stopped at α. Then, stop feeding any more hydraulic fluid.

This type of seven-kilometer relay circuit has the property that the actuator 3 moves quickly and in a constant manner under normal usage conditions, so for example, the clutch and transmission are included in the power transmission device. It is used in vehicles with automatic transmissions, etc. That is, in order to ensure that each operation of shifting the transmission after disengaging the clutch and reconnecting the clutch is performed, the actuator 3 in the accumulator circuit is used for connecting and disconnecting the clutch and shifting the transmission.
It is used.

[Problems to be Solved by the Invention] As described above, in the conventional accumulator circuit, although the actuator exhibits stable operation under normal usage conditions, when the oil temperature is low, the viscosity of the hydraulic oil increases. 7 until the oil temperature reaches the appropriate temperature.
The operation of the actuator is not constant, and there is a risk that devices driven by the actuator, such as the above-mentioned clutch and transmission, may not operate properly in cold regions. In addition, even if the hydraulic oil is at a low temperature, there is no means to bring it to the appropriate temperature in the conventional 7-cylinder regulator circuit. There was a problem, that I had to do it.

The object of the present invention is to provide extremely effective means for quickly eliminating such problems.

[Means to solve the problem]! The invention @1 is based on the above-mentioned 7-kilometer circuit,
A temperature sensor that detects the oil temperature is provided, a controller is provided that determines the oil temperature based on the detection signal from this temperature sensor, and when the controller determines that the oil temperature is below a predetermined value, a controller is provided in the accumulator circuit. The hydraulic pump is characterized by an oil temperature control device that continues the operation of the hydraulic pump in response to a command signal from the controller in order to circulate the hydraulic oil through the relief valve provided in the hydraulic pump.

Further, the second invention provides a sensor for detecting the load of the electric motor that drives the hydraulic pump in place of the temperature sensor,
The oil temperature control device is characterized in that a controller determines the oil temperature based on signals from this sensor, and when the temperature is low, operates a hydraulic pump to circulate the hydraulic oil via a relief valve.

Furthermore, the oil temperature control device according to the third aspect of the invention operates the controller to operate the hydraulic pump and circulate the hydraulic oil through the relief valve for a sufficient period of time for the oil temperature to reach the appropriate temperature at the time of startup. [Function 1] In the oil temperature control device in an accumulator circuit according to the first, second, and third inventions described above, by forcibly circulating the hydraulic oil, the low-temperature hydraulic oil is kept at an appropriate temperature. temperature can be raised quickly.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

Note that the same or equivalent parts as in the conventional (η configuration) will be described using the same reference numerals.

FIG. 1 shows an embodiment of an oil temperature control device for an accumulator circuit according to the first invention, and the accumulator circuit in this embodiment has the same structure as the conventional configuration shown above. Hydraulic oil pumped up from a tank 1 by a hydraulic pump 2 driven by an electric motor is accumulated in an accumulator 3, and then guided to a seven-actuator 5, such as a hydraulic cylinder, via a first solenoid valve 4, and then a second solenoid valve. Hydraulic oil from the actuator 5 is returned to the tank 1 via the actuator 6. Further, a relief valve 7 is provided at the opening of the hydraulic pump 2 and the pump 3 to protect the circuit.

A pressure sensor 8 is attached to the accumulator 3, and a signal is sent from the pressure sensor 8 to a controller 11 consisting of a microcomputer.

Further, a temperature sensor 12 that is attached to the tank 1 or the like and detects the temperature of the hydraulic oil is connected to the controller 11, and the controller 11 is connected to the hydraulic pump 2 in response to signals from the pressure sensor 8 and the temperature sensor 12. The electric motor 9 is now controlled.

To explain the operation in such a configuration, first, when the accumulator circuit starts operating,
The electric motor 9 rotates, the hydraulic pump 2 operates, and the hydraulic oil is sent to the 7-cumulator 3, where the pressure is accumulated. The controller 11 determines whether the pressure in the accumulator 3 has reached a predetermined value based on the signal from the pressure sensor 8. If the pressure has not reached the predetermined value, the electric motor 9 is further rotated to supply hydraulic fluid to the accumulator. Send it to 3. When the pressure inside the accumulator 3 reaches a predetermined value, the control by the controller 11 moves to the next step, and the 43
The oil temperature is cut off by p++. Here, if the oil temperature is low, the hydraulic oil is further pumped by the hydraulic pump 2,
As a result, the pressure in the circuit increases, the relief valve 7 opens, and the hydraulic oil circulates through this relief valve 7.
Oil temperature gradually rises. When the oil temperature becomes appropriate, the controller 11 stops the electric motor 9 and stops feeding the hydraulic oil, and as described above, an optimal condition for operating the seven cutout units 5 is obtained.

In this embodiment, the actuator 5 can be operated by controlling the solenoid valve 4.6 even in the oil temperature control state where the hydraulic oil is circulating through the IJ-7 valve 7. The solenoid valve 4.6 may be closed by a command signal from the controller 11 until the hydraulic oil reaches an appropriate temperature, and the actuator 5 may be moved only when the hydraulic oil reaches an appropriate temperature.

Also, FIG. 2 of the drawings shows the oil temperature 117 according to the invention of @1.
2 shows another embodiment of the control device. In this embodiment, a normally open third valve is connected between the relief valve 7 and the 7-cumulator 3.
A solenoid valve 13 is provided and is controlled by the controller 11. In this configuration, when the temperature sensor 12 detects that the oil temperature is low, the controller 11 issues a command signal in response to that signal to close the third solenoid valve 13. At this time, since the pressure inside the accumulator 3 is low, the oil temperature pump 2 continues to operate, and the oil temperature pump 2! The pressure at which the solenoid valve 13 of @3 opens increases, the relief valve 7 opens, and the hydraulic oil begins to circulate. When the hydraulic oil reaches an appropriate temperature through this circulation, the controller 11 demagnetizes the third solenoid valve 13 and returns it to the open state. From then on, as in a normal accumulator circuit, the hydraulic oil is accumulated in the accumulator 3. The hydraulic pump 2 is configured to stop when the internal pressure reaches a predetermined value.

Furthermore, as shown in the fjS3 diagram (, the relief pressure is smaller than the relief pressure of the relief valve 7 for circuit protection, and the accumulator 3
It is also conceivable to add a relief valve 14 dedicated to oil temperature control with a relief pressure smaller than the set pressure in the circuit. That is, a pipe line is led out from the upstream side of the relief valve 7 for circuit protection, and a relief valve 14 exclusively used for oil temperature control is attached via a normally closed solenoid valve 15. In such a configuration, when the oil temperature is low, the controller 11
When the solenoid valve 15 is opened, before the hydraulic oil is accumulated in the accumulator 3 to the set pressure, the ')')-7 valve 14 dedicated to oil temperature control opens and the hydraulic oil passes through this until it reaches the appropriate temperature. and circulate.

In addition, if the electric motor 9 for the hydraulic pump 2 is rated for a short time, the electric motor 9 may seize if the hydraulic pump 2 is rotated for a long period of time. It is preferable to provide a timer so that the electric motor 9 does not rotate for a time longer than the rated time of the electric motor 9.

Fig. Pt54 shows an oil temperature control device according to the second invention. In the illustrated embodiment, a temperature sensor is not provided in the accumulator circuit, but a sensor zO1 for detecting the load applied to the electric motor 9, such as a rotation speed detection sensor and a load current detection sensor, is provided. This is different from the embodiment shown in FIG. This second invention has been made in view of the fact that when the hydraulic oil is at a low temperature, the viscosity of the hydraulic oil is high and the load on the electric motor 9 also increases.
The oil temperature can be determined based on the signal from 0. Therefore, after the oil temperature is determined by the controller 11, the hydraulic oil can be circulated through the relief valve 7 until the oil temperature rises, similar to the embodiment of the first invention described above.

What is the embodiment of this second invention? It will be readily understood that many variations can be made, such as those made in the invention of tS1.

Furthermore, although not shown in the drawings, the oil temperature control device according to the third invention does not provide any type of sensor for detecting the oil temperature, and operates the electric motor for a certain period of time simultaneously with the start of the accumulator circuit. The controller is configured 411'l to issue a command signal to continue the movement. As the time for rotating the electric motor during this startup,
For example, if the time required to raise the oil temperature to the proper oil temperature by circulating the hydraulic oil through the relief valve from the lowest possible oil temperature is stored in the controller's memory. At the time of startup, the hydraulic oil is always circulated through the relief valve, as in the various embodiments described above, so the temperature of the hydraulic oil is always controlled at an appropriate temperature.

[Effect of the invention 1 As described above, according to the inventions fIfJl, No. 2, and fjrJ3, low oil temperature can be shortened by a simple method of forcibly circulating the hydraulic oil through the relief valve under control of the controller. The temperature can be raised to the appropriate temperature in time. Therefore, unstable operation of the actuator caused by low oil temperature is quickly resolved, and the operation of the device driven by the actuator can be stabilized.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of an oil temperature control device in an accumulator circuit according to the first invention. @ Figure 2 is a schematic explanatory diagram showing another embodiment of the invention No. 11, Figure 3 is a schematic explanatory diagram showing yet another embodiment of the invention No. 1, and Figure 4 is an oil temperature diagram according to the invention of f52. A schematic explanatory diagram showing one embodiment of the control device, FIG. 5 is a diagram showing a conventional 7-cumulator circuit. In the figure, 1: tank, 2: hydraulic pump, 3: 7 cylinder, 5: actuator, 7.14: relief valve,
9: Electric motor, 8: Pressure sensor, 11: Controller, 12: Temperature sensor, 20: Load detection sensor Patent applicant: Toy manager at Toyoda Automatic Miso Seisakusho Co., Ltd.
@91 8□(5) Ripe Figure 1 Figure 3

Claims (1)

[Claims] 1. A tank for storing hydraulic oil, a hydraulic pump for pumping the hydraulic oil, an accumulator for accumulating the pressure of the hydraulic oil sent from the hydraulic pump, and the hydraulic oil accumulated in the accumulator. an actuator operated by the
The accumulator circuit is configured to stop the hydraulic pump when the pressure in the accumulator reaches a predetermined value, and a temperature sensor for detecting oil temperature is provided, and the oil temperature is determined based on a detection signal from the temperature sensor. A controller is provided, and when the controller determines that the oil temperature is below a predetermined value, a command signal is sent from the controller to circulate the hydraulic oil through a relief valve provided in the accumulator circuit. An oil temperature control device in an accumulator circuit that causes the hydraulic pump to continue operating. 2. A tank for storing hydraulic oil, a hydraulic pump for pumping the hydraulic oil, an accumulator for accumulating pressure of the hydraulic oil sent from the hydraulic pump, and an actuator operated by the hydraulic oil accumulated in the accumulator. Equipped with
In an accumulator circuit configured to stop the hydraulic pump when the pressure within the accumulator reaches a predetermined value, a sensor is provided to detect a load on an electric motor that drives the hydraulic pump, and the sensor detects the load of the electric motor that drives the hydraulic pump. A controller is provided that determines the oil temperature based on a signal, and when the controller determines that the oil temperature is below a predetermined value, the hydraulic oil is circulated through a relief valve provided in the accumulator circuit. An oil temperature control device in an accumulator circuit that causes the hydraulic pump to continue operating according to a command signal from the controller. 3. A tank for storing hydraulic oil, a hydraulic pump for pumping the hydraulic oil, an accumulator for accumulating pressure of the hydraulic oil sent from the hydraulic pump, and an actuator operated by the hydraulic oil accumulated in the accumulator. Equipped with
In the accumulator circuit that is configured to stop the hydraulic pump when the pressure in the accumulator reaches a predetermined value, the accumulator circuit is provided for a sufficient period of time for the oil temperature to reach the appropriate temperature at the time of startup. An oil temperature control device in an accumulator circuit, which includes a controller that issues a command signal to continue operating the hydraulic pump in order to circulate the hydraulic oil through a relief valve.