JP3883155B2 - Fan hydraulic drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention drives a radiator cooling fan with a hydraulic motor, drives the hydraulic motor with pressure oil supplied by a hydraulic pump driven by an engine, and supplies an oil cooler and an oil to a hydraulic circuit that returns from the hydraulic motor to an oil tank. The present invention relates to a fan hydraulic drive device that includes a filter.
[0002]
[Prior art]
For example, Japanese Patent Application No. 9-16715 discloses a prior art of such a fan hydraulic drive apparatus. The configuration of a radiator cooling fan hydraulic drive apparatus using a hydraulic motor in such a prior art is shown in FIG. Is shown in
[0003]
A fan F that cools a radiator (not shown) is driven by a hydraulic motor 1 constituted by a plunger motor. The hydraulic motor 1 includes a gear pump 2a driven by an engine E and reliefs including relief valves 2b and 2c. The hydraulic oil is supplied from the hydraulic pump 2 constituted by the circuit 2m by the hydraulic circuit L1 and driven.
[0004]
An oil cooler 19 and an oil filter 7 are interposed in the return circuit L2 from the hydraulic motor 1 to the oil tank 8, and the oil cooler 19 is prevented from being applied with a pressure higher than a predetermined pressure. The oil filter 7 has a built-in bypass valve 7b for performing a shortcut when the flow resistance is excessive.
[0005]
Also, a circuit L4 that branches from the relief circuit 2m of the hydraulic pump 2 and returns to the oil tank 8 via an oil temperature thermo valve 14 that opens when the oil temperature exceeds a predetermined value, and cooling in parallel with this circuit L4 A circuit L3 is provided to return to the oil tank 8 via a water temperature thermo valve 15 that opens when the water temperature is equal to or higher than a predetermined value.
[0006]
Therefore, according to such a configuration, when the oil temperature is low and the viscosity of the oil is high at the time of low temperature start or the like, the oil temperature thermo valve 14 is opened and the circuit L4 is connected from the discharge side of the pump 2 to the oil tank 8. Thus, the oil flow is relieved to protect the device, and excessive driving power is prevented. Further, when the cooling water temperature is low, the oil temperature is returned to the tank 8 by the circuit L3 by the water temperature thermo valve 15, and the warm-up is promoted by reducing the rotation of the fan F to a low speed, and the drive power is reduced. The economy is improved.
[0007]
The hydraulic motor 1 is connected to the hydraulic circuits L1 and L2 via the counter balance valve 3, and when the supply oil is suddenly cut, the motor 1 rotates by the inertia of the fan to act as a pump. Further, it is possible to prevent a negative pressure from being generated on the motor inlet side to cause problems such as cavitation.
[0008]
That is, the counter balance valve 3 is provided with a switching valve 3a that operates at the hydraulic pressure before the motor downstream of the hydraulic motor 1, and passes through the check valve 3b from the downstream of the motor and the check valve 3c from the downstream of the switching valve 3a. A circuit that returns to the front of the motor is provided. During normal operation, the switching valve 3a moves to the right in the figure by the hydraulic pressure of the circuit L1, and the downstream of the motor communicates with the circuit L2. When the negative pressure is detected on the motor inlet side, the check is made from the outlet side to the inlet side. Oil is supplied through the valve 3b. When the hydraulic pressure on the circuit L1 side decreases and the switching valve 3a is on the left side, this serves as a throttle, and oil is supplied upstream of the motor via the check valve 3b.
[0009]
However, in such a conventional fan hydraulic drive device, since the hydraulic pressure of the circuit L2 is increased, the oil cooler 19 is controlled by the oil temperature by providing the short valve 16 and the discharge side of the hydraulic pump 2. For example, the relief circuit L4 is provided to have a complicated structure for pressure resistance. The water temperature thermovalve 15 is generally controlled by a wax pellet element, and the flow rate is controlled with respect to the water temperature. However, as indicated by the chain line B in FIG. At a low temperature of 90 ° C. or less, the fan F is operated at a low speed, and when the temperature exceeds a predetermined temperature, the fan F is set to change to a high speed operation. From the viewpoint of economy, it is preferable that the fan F stops rotating at a low temperature, and when the temperature rises and the fan F is turned on, it is preferable that a rapid increase in rotation is not performed in terms of noise and the like.
[0010]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-described conventional technology, and an object thereof is to provide a hydraulically driven cooling fan device that is simple in structure and light in weight, and has excellent cooling efficiency and durability even in the cold season. And
[0011]
[Means for Solving the Problems]
According to the present invention, the cooling target fan (F) is driven by the hydraulic motor (1), and the hydraulic motor (1) is driven by the pressure oil supplied by the hydraulic pump (2) driven by the engine. An oil cooler (9) and an oil filter (7) are interposed in the hydraulic circuit (L2) returning from the hydraulic motor (1) to the oil tank (8), and branch off from the discharge side of the hydraulic pump (2). A circuit (L3) that returns to the oil tank (8) through a water temperature thermo valve (5) that operates at the cooling water temperature is provided, and the rotation of the fan (F) is controlled by the water temperature thermo valve (5) In the hydraulic drive device, the water temperature thermo valve (5) includes a valve pellet (52) enclosing a plurality of types of wax (64a, 64b) and a wax pellet element (6) that operates by volume expansion of the wax and a spring ( 54) and The rotation of the fan (F) is stopped when the temperature is lower than a predetermined temperature, and when the temperature is higher than the predetermined temperature, the opening of the thermo valve (5) corresponding to the cooling water temperature is set as the fan rotation speed with respect to the cooling water temperature. The characteristic changes in a plurality of stages from a characteristic having a small change in rotational speed with respect to a change in cooling water temperature to a characteristic having a large change in rotational speed with respect to a change in cooling water temperature.
[0014]
In addition, it is preferable to use the thing of the system excellent in pressure | voltage resistance as the oil cooler interposed in the hydraulic circuit which returns to an oil tank from a hydraulic motor.
[0015]
Therefore, according to the above configuration, the water temperature thermovalve installed in the circuit branched from the discharge side of the hydraulic pump detects the cooling water temperature, changes the opening area, and increases the opening area below a predetermined temperature. Return the hydraulic pump discharge oil amount to the oil tank, cut the flow rate to the hydraulic motor and stop the rotation of the fan, and reduce the return oil amount to the tank to reduce the return oil amount to the tank by narrowing the opening area above the specified temperature. The flow rate is increased and the fan is rotated at a predetermined rotational speed, so that warm-up performance and economic efficiency are improved.
[0016]
And, by enclosing multiple types of wax and operating the water temperature thermo valve with the wax pellet element that operates by the volume expansion of the wax, the operating range of the valve opening area is expanded, and the rise is not abrupt, but a broken line shape Therefore, the fan can be stopped when the temperature is low, and no noise or impact is generated when the fan rotates.
[0018]
A circuit is provided to return to the oil tank via a water temperature thermo valve that branches off from the discharge side of the hydraulic pump and operates at a cooling water temperature. The water temperature thermo valve encloses a plurality of types of wax and the volume of the wax. A wax pellet element that operates by expansion is provided, and the fan is stopped when the cooling water temperature is lower than a predetermined temperature, and is rotated at a predetermined rotation speed according to the cooling water temperature when the cooling water temperature is lower than the predetermined temperature.
[0019]
According to the above configuration, the negative pressure is generated at the inlet / outlet of the hydraulic motor, for example, even if the engine stops and the oil supply to the motor stops, the motor continues to rotate due to the inertia of the fan. In this case, the oil is supplied from the downstream side of the counter balance valve to the negative pressure side via the check valve, so that problems such as the occurrence of cavitation are prevented. The counter balance valve is configured symmetrically with respect to the upstream and downstream directions of the motor, and is effective for both forward and reverse rotations of the fan.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same component as the conventional fan hydraulic drive unit demonstrated in the said FIG. 10, and the overlapping description is abbreviate | omitted.
[0021]
FIG. 1 shows a configuration of a radiator cooling fan hydraulic drive apparatus using a hydraulic motor 1 according to the present invention. A circuit L3 in which a water temperature thermo valve 5 is interposed branches from a relief circuit 2m of the hydraulic pump 2 driven by the engine E, and the circuit L3 is returned to the oil tank 8. The oil cooler 9 interposed in the circuit L2 that returns from the hydraulic motor 1 to the oil tank 8 is one having excellent pressure resistance. The short valve 16 and the oil temperature thermostat described in the prior art are used. The circuit L4 interposing the valve 14 is not incorporated. In addition, what is shown with the code | symbol C in the figure is the aperture | diaphragm | restriction provided in the channel | path.
[0022]
As shown in FIG. 2, the water temperature thermo valve 5 provided in the circuit L3 has an inlet 5a formed at one end of a cylindrical thermo valve main body 51, and a wax pellet element 6 for detecting the cooling water temperature at the other end (for details, see FIG. (Described later) is screwed, and a side surface is provided with an outlet 5b. A valve body 52 is urged by a spring 54 inside the inlet 5 a in the main body 51, and the piston tip of the wax pellet element 6 is connected to the other end of the spring 54 via a spring seat 53. It is in contact.
[0023]
As shown in FIG. 3, the wax pellet element 6 is provided with a piston 62 wrapped in a rubber sleeve 63 in a metal cup 61, and there are two types between the sleeve 63 and the cup 61. Waxes 64a and 64b are enclosed. The element 6 is inserted in the cooling water, and when the cooling water temperature rises, the piston 62 in the sleeve 63 is pushed out by the volume expansion of the waxes 64a and 64b, but the two types of waxes 64a and 64b are selected by their expansion characteristics. As shown by a solid line A in FIG. 4, the air temperature is lifted from the water temperature t <b> 1, becomes a polygonal line at t <b> 2, and reaches a full lift at t <b> 3. In FIG. 4, the horizontal axis represents the cooling water temperature, the vertical axis represents the valve lift (stroke of the piston 62), and the characteristics of the conventional element are shown in comparison by a chain line B.
[0024]
In other words, FIG. 4 shows the characteristics of the cooling water temperature and the number of rotations. According to the illustrated embodiment, the rotation with respect to the cooling water temperature changes in the region where the cooling water temperature is t1-t2 at a predetermined temperature t1 or higher. The characteristic is set so that the number change is small, and in the region where the cooling water temperature is t2-t3, the characteristic is set so that the rotational speed change with respect to the cooling water temperature change is large. The rotational speed characteristic changes in a plurality of stages.
[0025]
In FIG. 4, the cooling water temperature-rotational speed characteristic changes in two stages, but can be changed in more stages. Of course, it is possible to change to full lift suddenly or to change in one step.
[0026]
Therefore, the operation of the water temperature thermovalve 5 has a relationship of the opening area (vertical axis) to the cooling water temperature (horizontal axis) as shown by the solid line A in FIG. (The chain line B shows the characteristics of the conventional product.)
Next, the operation of the present invention will be described with reference to FIG.
The cooling water circulates in the engine and the temperature rises (81). The wax pellet element 6 inserted in the cooling water detects the cooling water temperature (82), and the piston 62 is lifted with the characteristics shown in FIG. That is, it is not lifted up to the water temperature t1, it is a polygonal line at the water temperature from t1 to t3, and it is full lift at t3 or higher. By the operation of this element 6, the water temperature thermo-valve 5 is fully opened (83) when the water temperature is t1 or less, as shown in FIG. 5, and the opening area is reduced in a polygonal line as the water temperature rises between t1 and t3 (86). Then it is fully closed (89). With the operation of the water temperature thermo valve 5, the amount of relief oil from the hydraulic pump 2 decreases, the amount of oil supplied to the hydraulic motor through the circuit L1 increases, and the fan F starts from a stop (85) below the water temperature t1. The rotation rises (88), and full rotation is reached after t3 (91). Then, the cooling water in the radiator is cooled by the air volume generated by the rotation of the fan F (92), and returns to the engine again.
[0027]
With the operation described above, the relationship between the cooling water temperature (horizontal axis) and the fan rotation speed (vertical axis) is as shown by a solid line A in FIG. That is, the fan F does not rotate until the water temperature t1 (76.5 degrees C), gradually increases from t1 (76.5 degrees C) to t2 (90 degrees C), and after t3 (95 degrees C) or more. Full rotation. In addition, the characteristic by a prior art is compared and shown by the dashed line B in the figure.
[0028]
The relationship between the engine speed (horizontal axis) and the fan speed (vertical axis) is as shown in FIG. That is, at a low engine load, the water temperature is t1 or less and the fan F does not rotate as indicated by the straight line L. The fan F rotates as indicated by a straight line H at a high load at which the water temperature is equal to or higher than t3. In the load during this time, the fan F rotates between L and H depending on the water temperature. For example, if the economical operation is performed at a water temperature of 90 degrees, the fan F rotates as shown by the straight line M.
[0029]
FIG. 9 shows another embodiment in which the counter balance valve is different from the above embodiment.
In the figure, the hydraulic motor 1 is connected to hydraulic circuits L1 and L2 via a counter balance valve 3A. The counter balance valve 3A communicates from a circuit L5 branched from the downstream circuit L2 via check valves 33 and 34 respectively upstream and downstream of the hydraulic motor 1, and is switched in parallel with the check valves 33 and 34. 31 and 32 are provided, respectively.
[0030]
According to such a configuration, when the engine E is stopped and the oil supply to the hydraulic motor 1 is stopped, the fan F is rotated by inertia and the hydraulic motor 1 performs a pumping action to generate a negative pressure on the inlet side. Since oil is supplied to the upstream side from the downstream circuit L5 via the check valve 33, problems such as cavitation are prevented. Since the counter balance valve 3A is configured symmetrically with respect to the upstream and downstream of the motor 1, the counter balance valve 3A is effective against both forward and reverse rotations of the fan F, and the structure can be easily configured.
[0031]
【The invention's effect】
The present invention is configured as described above, and has the effect shown.
(1) Fan rotation stops when the temperature is lower than the predetermined temperature, and when the fan rotation is higher than the predetermined temperature, the rotation starts slowly. Therefore, economic efficiency and warm-up performance are improved, and noise and impact are reduced when the fan is turned on. The
(2) It is possible to eliminate the oil temperature thermo valve and its circuit that operate by detecting the oil temperature, or the (bypass) short valve of the oil cooler.
(3) The performance of the counter balance valve is improved, and it can be made smaller and simpler than conventional products.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an embodiment of a water temperature thermovalve used in the present invention.
3 is a cross-sectional view showing an embodiment of a wax pellet element used in the water temperature thermo valve of FIG. 2;
FIG. 4 is a graph showing valve lift characteristics of the present invention and a conventional wax pellet element.
FIG. 5 is a view showing an opening area of the present invention and a conventional water temperature thermo valve.
FIG. 6 is a diagram showing a relationship between cooling water temperature and fan rotation speed.
FIG. 7 is a diagram showing the relationship between engine speed and fan speed.
FIG. 8 is a flowchart for explaining the operation.
FIG. 9 is an overall configuration diagram showing another embodiment of the present invention.
FIG. 10 is an overall configuration diagram showing a conventional fan hydraulic drive device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hydraulic motor 2 ... Hydraulic pump 2a, 2b ... Relief valve 2m ... Relief circuit 3, 3A ... Counter balance valve 3a, 31, 32 ... Switching valve 3b, 3c, 33 34, check valve 5, 15 ... water temperature thermo valve 6 ... wax pellet element 62 ... piston 64a, 64b ... wax 7 ... oil filter 8 ... oil tank 9, 19 ... Oil cooler E ... Engine F ... Fan

Claims (1)

  The cooling target fan (F) is driven by a hydraulic motor (1), the hydraulic motor (1) is driven by pressure oil supplied by a hydraulic pump (2) driven by an engine, and the hydraulic motor ( 1) From the hydraulic circuit (L2) returning from the oil tank (8) to the hydraulic circuit (L2), an oil cooler (9) and an oil filter (7) are interposed, and the water temperature branches off from the discharge side of the hydraulic pump (2) and operates at the coolant temperature In the fan hydraulic drive device provided with a circuit (L3) for returning to the oil tank (8) through the thermo valve (5) and controlling the rotation of the fan (F) by the water temperature thermo valve (5), The water temperature thermo-valve (5) is energized by a wax pellet element (6) and a spring (54) whose valve body (52) encloses a plurality of types of wax (64a, 64b) and operates by volume expansion of the wax. Has been The rotation of the fan (F) is stopped below a predetermined temperature, and the opening of the thermo valve (5) corresponding to the cooling water temperature is exceeded above the predetermined temperature. A fan hydraulic drive apparatus characterized by having a characteristic that changes in a plurality of stages from a characteristic having a small change in rotational speed to a characteristic having a large change in rotational speed with respect to a change in cooling water temperature.

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