JPH0144810Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature sensitive fluid coupling for an engine cooling fan.

Generally, a temperature-sensitive fluid coupling for an engine cooling fan includes a shaft rotated by the engine, a rotor fixed to the tip of the shaft, and a rotor fixed to the tip of the shaft.
a housing rotatably assembled on the shaft to accommodate the rotor and working fluid and to which a cooling fan is attached; A partition member that partitions the working chamber into an oil storage chamber that stores the working fluid that flows back from the working chamber, and a valve member that opens and closes a through hole provided in the partition member, and the valve member is actuated by a rise in engine temperature. to open the through hole of the partition member,
The working fluid in the oil storage chamber is configured to flow into the working chamber. In addition, in this type of temperature-sensitive fluid coupling, a temperature-sensitive spiral member such as a spiral bimetal is used as the temperature-sensitive member, and the temperature of the air passing through the radiator is sensed by the temperature-sensitive spiral member to operate the valve member. It is composed of
Therefore, according to this kind of conventional temperature-sensitive fluid coupling, the inflow of the working fluid into the working chamber is controlled according to the temperature of the air passing through the radiator, and the rotational speed of the cooling fan is also controlled according to the temperature of the air. will be done. However, the temperature of the air fluctuates depending on the time and amount of air passing through the radiator, and does not necessarily correspond to the engine temperature, so the rotational speed of the cooling fan cannot be accurately controlled in accordance with the engine temperature.

In order to deal with such problems, the applicant has proposed a temperature-sensitive fluid coupling that operates a valve member according to the temperature of engine cooling water, in Utility Model Application No. 56-19860 (Utility Model Application No. 57-132026). It is proposed in The temperature-sensitive fluid coupling includes a partitioning member that partitions the oil storage chamber in the housing into a variable pressure chamber and a constant pressure chamber, and a pushing force that moves due to the pressure difference between these two chambers to operate the valve member. The variable pressure chamber is connected to a pressure source that is controlled according to the temperature of the engine cooling water, and the pressure in the variable pressure chamber is changed by the temperature rise of the engine cooling water. The pressure difference between the variable pressure chamber and the constant pressure chamber is configured to operate the valve member via the pushing member to open the through hole of the partition member. Therefore, according to the temperature-sensitive fluid coupling, the inflow of the working fluid into the working chamber is controlled according to the temperature of the engine cooling water, and the shearing action generated by the working fluid in the working chamber is adjusted. The rotational speed of the cooling fan is controlled according to the engine temperature. However, since the constant pressure chamber is configured in a closed state even in the temperature-sensitive fluid coupling, the internal pressure of the constant pressure chamber fluctuates due to a rise in the temperature of the working fluid, making the operation of the pushing member unstable. Therefore, the operation of the valve member may become unstable.

The present invention is to stabilize the operation of the valve member by always keeping the internal pressure of the constant pressure chamber constant in the temperature-sensitive fluid coupling, thereby accurately controlling the rotational speed of the cooling fan in accordance with the engine temperature.

Hereinafter, the present invention will be explained based on the drawings. FIG. 1 shows an example of a temperature-sensitive fluid coupling (hereinafter sometimes referred to as a fluid coupling) according to the present invention. This fluid coupling increases the rotational speed of the cooling fan by 3
It is a fluid coupling that can be controlled in stages, and the drive system member 1
0, the main components are a driven system member 20, a valve device 30, a pressure actuating device 40, and a pressure source control device 50.

The drive system member 10 of the fluid coupling consists of a shaft 11 that is rotatably driven by an engine and a rotor 12 fixed to the tip thereof. A flange portion 1 is fitted onto the tip and fixed onto the support rod 14.
5 is integrally attached and fixed together with the pulley 16. Further, the driven system member 20 includes a housing 21 rotatably assembled onto the shaft 11 via a shield bearing, and a plurality of outer through holes 22a.
and an annular partition plate 22 with an inner through hole 22b.
The partition plate 22 is attached to the intermediate member 21b of the housing 21 and is connected to the cylindrical portion 12 of the rotor 12.
a Front member 2 of the housing 21 located on the outer periphery
An oil storage chamber R1 is formed on the side 1a, and the housing 21
A working chamber R2 is formed on the rear member 21c side. The working chamber R2 accommodates the disk portion 12b of the rotor 12, and has a shearing space 1 between the disk portion 12b and the rear member 21c and between the disk portion 12b and the partition plate 22.
2c and 12d are formed. As a result, when the rotor 12 rotates, the housing 21 is moved by the shearing action of the hydraulic oil present in the shearing spaces 12c and 12d.
As the cooling fan (not shown) is rotated, the hydraulic oil present in the working chamber R2 is pumped between the rotor 12 and the housing 21, and the hydraulic oil is pumped into the oil storage chamber R1.
Reflux to. Further, the hydraulic oil in the oil storage chamber R1 is supplied to each through hole 2 of the partition plate 22 by the operation of a valve device 30, which will be described later.
When 2a and 22b are opened, the hydraulic oil flows into the working chamber R2 through the through holes 22a and 22b, increasing the shearing action of the hydraulic oil and increasing the rotational speed of the housing 21 and the cooling fan.

Therefore, within the housing 21, a valve device 30 is provided.
and a pressure actuation device 40 are provided. Valve device 3
0 consists of a first valve plate 31 and a second valve plate 32, and a first spring 33 and a second spring 34 that urge both valve plates 31 and 32 rearward, respectively.
Further, the pressure actuating device 40 includes a push rod 41,
It consists of a first spring 44 that biases the diaphragm 42, the valve body 43, and the push rod 41 forward, and a second spring 45 that biases the valve body 43 rearward. The first valve plate 31 is a plate spring having a predetermined width, and has a retainer 31a in its center, and opens and closes the through hole 22a with its legs 31b. Further, the second valve plate 32 includes two sets 32a, 32b of a pair of leg parts branched into two on both sides of the annular plate, and these leg parts 32a,
32b opens and closes the through hole 22b. First valve plate 31
The leg portion 31b is inserted between the branch leg portions of the second valve plate 32. The inner circumferential edge of a diaphragm 42 whose outer circumferential line is fixed to the tip of the cylindrical portion 12a of the rotor 12 is fixed to the rear end of the push rod 41, and a cylindrical guide member 46 fixed to the tip of the cylindrical portion 12a of the rotor 12 is guided in the front-rear direction. It penetrates so that it can be moved to.
Further, a cylindrical retainer 47 is fixed to the rear end of the push rod 41, and a second spring 45 interposed in the cylindrical retainer 47 applies a biasing force to the valve body 47.
3 is in contact with the rear end flange portion of the cylindrical retainer 47. The push rod 41 is a first push rod inserted between the diaphragm 42 and the tip of the shaft 11.
It moves forward under the biasing force of the spring 44 and engages with the first valve plate 31 via the ball 42a and the retainer 31a, and the first valve plate 31 is moved forward by the first spring 3.
3, and the second valve plate 32 is bent forward via the first valve plate 31 against the second spring 34. In this state, the first valve plate 31 opens the outer passage hole 22a of the partition plate 22, and the second valve plate 32 opens the inner passage hole 22b of the partition plate 22. Further, the diaphragm 42 forms a constant pressure chamber ra on its front side and a variable pressure chamber rb on its rear side. The constant pressure chamber ra communicates with the atmosphere, and the variable pressure chamber rb communicates with a negative pressure source via a pressure control device 50.

That is, a through hole 21d is formed in the central recess of the front member 21a of the housing 21, and the air filter 24 is attached to this recess via a mounting member 23. Thereby, the constant pressure chamber ra formed in the oil storage chamber R1 communicates with the atmosphere through the air filter 24. On the other hand, a protrusion 11a that protrudes into the variable voltage chamber rb is formed at the axial center of the shaft 11. A valve body 43 is seated at the tip of the protruding portion 11a, and a through hole 14a provided at the axis of the support rod 14 and a through hole 11b communicating with the variable pressure chamber rb are formed in this portion. Also, shaft 11
A through hole 14b provided outside the through hole 14a of the support rod 14 and a variable pressure chamber rb are provided outside the through hole 11b of the support rod 14.
A through hole 11c is formed which communicates with the. This through hole 14a has both shield bearings 17a and 17b.
It communicates with the annular chamber rc formed between, and the through hole 14
b communicates with an annular chamber rd formed on the rear side of the shield bearing 17b.

The pressure control device 50 consists of two 3-port 2-position switching valves 51 and 52, which are bimetallic vacuum switching valves.
52 integrally includes bimetals 51a and 52a. Each bimetal 51a, 52a has a plate shape, and switches the passage using a snap action (reversal of unevenness) caused by a temperature change. The switching valve 51 communicates with an intake manifold 55 of the engine and an annular chamber rc via pipes 53 and 54,
The switching valve 52 also communicates with the intake manifold 55 and the annular chamber rd via pipes 53 and 56. When the temperature of the engine cooling water is low, the switching valves 51 and 52 communicate the variable pressure chamber rd with the intake manifold 55 in the state shown in the first diagram by the action of the bimetals 51a and 52a. Further, when the temperature of the engine cooling water rises and reaches a predetermined medium temperature, the switching valve 52 is switched to the bimetal 52a.
Due to the reversal action of
The variable pressure chamber rb communicates with the intake manifold 55 via the switching valve 51 and with the atmosphere via the switching valve 52 and the throttle 52b. When the temperature of the engine cooling water further rises and reaches a predetermined high temperature, the switching valve 51 also switches to the right in the first figure and enters the state shown in the third figure, and the transformation chamber rb switches both the switching valves 51 and 52. through which it communicates with the atmosphere. Therefore, when the engine is stopped, atmospheric air is applied to the variable pressure chamber rb, and when the engine is running, a predetermined high negative pressure is applied when the engine cooling water temperature is low, and a predetermined low negative pressure is applied when the water temperature is medium. Negative pressure is applied to the variable pressure chamber rb, and when the water temperature is high, the atmosphere is applied to the variable pressure chamber rb.

The fluid coupling thus constructed is in the state shown in FIG. 1 when the engine is stopped. That is, both switching valves 51 and 52 of the pressure control device 50 are located on the left side in the figure and communicate the variable pressure chamber rb with the intake manifold 55;
Since no negative pressure is generated in the variable pressure chamber rb, the pressure is at atmospheric pressure. Therefore, the push rod 41 is moving forward under the biasing force of the first spring 44, and resists both springs 33 and 34 to push both valve plates 3
1 and 32 are bent, and both through holes 2 of the partition plate 22
2a and 22b are open. Further, the valve body 43 is moved around the cylindrical retainer 47 by the urging force of the second spring 45.
It is in contact with the rear end of.

Therefore, when the engine is driven, if the temperature of the engine cooling water is low, both the switching valves 51 and 5
2 is still in the position shown in FIG.
1 and 52 to the variable pressure chamber rb. Therefore, a pressure difference is generated between the constant pressure chamber ra and the variable pressure chamber rb, and the push rod 41 moves rearward against the first spring 44, as shown in FIG. As a result,
The valve body 43 is seated on the tip of the protruding portion 11a of the shaft 11, and both valve plates 31 and 32 are released from deflection to close both the through holes 22a and 22b of the partition plate 22. Therefore, when the temperature of the engine cooling water is low, the hydraulic oil that has returned from the working chamber R2 to the oil storage chamber R1 does not flow into the working chamber R2, but instead flows into the working chamber R2.
The rotation of the shaft 11 is transmitted to the housing 21 by the shearing action caused by a small amount of hydraulic oil.
A cooling fan (not shown) integrated with the housing 21 rotates at a low speed. Note that during this time, the valve body 43 is maintained seated on the tip of the protrusion 11a of the shaft 11,
After seating, negative pressure is applied to the variable pressure chamber rb through the switching valve 52.

Further, when the engine cooling water rises and reaches a predetermined medium temperature, only the switching valve 52 is turned off by the bimetal 52a.
The switching operation is performed to the right in the second figure by the reversal action of
Atmosphere is added to rb. As a result, the pressure difference between the constant pressure chamber ra and the variable pressure chamber rb decreases, and the first spring 4
4, the push rod 41 moves forward against the spring 33. During this time, the valve body 43
is maintained seated on the protruding portion 11a of the shaft 11 by the action of the second spring 45 and the negative pressure from the annular chamber rc, and the push rod 41 is maintained in position when the valve body 43 engages with the rear end flange portion of the cylindrical retainer 47. At that point, its forward movement is restricted. Therefore, the push rod 41 is located approximately midway between the first and second figures, and bends only the first valve plate 31 to open only the outer passage hole 22a of the partition plate 22. Therefore, the hydraulic oil that has returned to the oil storage chamber R1 flows into the working chamber R2 through the outer passage hole 22a, and the rotation of the shaft 11 is transmitted to the housing 21 by the shearing action generated by the increased amount of hydraulic oil, and the cooling fan is Rotates at medium speed. In addition, during this time, if the valve body 43 is temporarily closed to the shaft 1.
Even if the valve body 43 is separated from the tip of the protruding portion 11a of the push rod 41, the negative pressure in the annular chamber rc is instantaneously applied to the variable pressure chamber rb, so that the valve body 43 is instantaneously seated at the tip and maintains the current position of the push rod 41. Hold.

Furthermore, when the engine cooling water rises and reaches a predetermined high temperature, not only the switching valve 52 but also the switching valve 51 is switched to the right in the second figure due to the reversal action of the bimetal 51a, and the state shown in the third figure is reached. Then, the atmosphere is applied to the variable pressure chamber rb through both the switching valves 51 and 52, and the pressure difference between the constant pressure chamber ra and the variable pressure chamber rb disappears.
Therefore, the push rod 41 further moves forward against both springs 33 and 34, bends the second valve plate 32, and also opens the inner through hole 22b of the partition plate 22. As a result, the hydraulic oil that has returned to the oil storage chamber R1 flows into the working chamber R2 through both the through holes 22a and 22b, and the rotation of the shaft 11 is prevented by the shearing action caused by the increased amount of hydraulic oil.
1, and the cooling fan rotates at high speed.

In this way, in the fluid coupling, the amount of hydraulic oil flowing into the working chamber R2 is controlled according to the temperature of the engine cooling water, so the rotational speed of the cooling fan can be controlled according to the engine temperature. I can do it. In addition, in this fluid coupling, the constant pressure chamber ra formed in the oil storage chamber R1 is communicated with the atmosphere, so even if the temperature of the hydraulic oil etc. rises, the constant pressure chamber ra
The internal pressure of RA can be kept constant at all times, the operation of both valve plates 31 and 32 by the push rod 41 can be stabilized, and the rotational speed of the cooling fan can be accurately controlled according to the engine temperature.

In addition, in this embodiment, an example of a fluid coupling that can control the rotational speed of a cooling fan in three stages using negative pressure has been shown, but the valve device 30, pressure actuation device 40, pressure control device 50, etc. can be changed. By doing so, it is possible to create a fluid coupling that can control the rotation speed of the cooling fan in multiple stages of two or more stages, and a fluid coupling that can control the rotation speed of the cooling fan using compressed air instead of negative pressure. can do. For example, in the above embodiment, the number of valve plates 31, 32 and corresponding through holes 22a, 22b, the number of variable pressure chambers,
By appropriately setting the number of means for applying negative pressure to rb, it is possible to control the rotation speed of the cooling fan in multiple stages.

[Brief explanation of drawings]

The drawings are longitudinal cross-sectional views showing an example of the fluid coupling according to the present invention, in which Fig. 1 is a longitudinal cross-sectional view when the engine is stopped, and Fig. 2 is a longitudinal cross-sectional view when the engine is running and the temperature of the engine cooling water is low. Longitudinal cross-sectional view of
FIG. 3 is a longitudinal sectional view when the temperature of the engine cooling water is high. Explanation of symbols, 11...Shaft, 12...Rotor, 21...Housing, 21d...Through hole, 22
...Partition plate, 22a, 22b...Through hole, 31, 3
2... Valve plate, 41... Push rod, 42...
Diaphragm, 51, 52...Switching valve, R1...
Oil storage chamber, R2... working chamber, ra... constant pressure chamber, rb...
Transformer room.

Claims (1)

[Scope of utility model registration request] A shaft rotationally driven by an engine, a rotor fixed to the tip of the shaft, a housing rotatably assembled on the shaft to accommodate the rotor and working fluid, and to which a cooling fan is attached; A partition member disposed in the partition member and partitioning the inside thereof into a working chamber that accommodates the rotor and produces a shearing action on the working fluid, and an oil storage chamber that stores the working fluid that flows back from the working chamber, and a passage provided in the partition member. An engine cooling fan comprising a valve member that opens and closes a hole, the valve member being actuated by a rise in engine temperature to open a through hole in the partition member and allowing working fluid in the oil storage chamber to flow into the working chamber. In the temperature-sensitive fluid coupling, the oil storage chamber is provided with a partitioning member that partitions the interior thereof into a variable pressure chamber and a constant pressure chamber, and a pushing member that moves due to a pressure difference between these two chambers and operates the valve member, On the other hand, the variable pressure chamber is communicated with a pressure source controlled according to the temperature of the engine cooling water, and the constant pressure chamber is communicated with the atmosphere to change the pressure of the variable pressure chamber by increasing the temperature of the engine cooling water;
Temperature-sensitive fluid for an engine cooling fan, characterized in that the pressure difference between the variable pressure chamber and the constant pressure chamber operates the valve member via the pushing member to open the through hole of the partition member. Fittings.