JPS61228131A - Viscous fluid coupling - Google Patents

Abstract

PURPOSE:To prevent wearing in point end parts of both a transmission rod and a valve rod, by fixing a valve stopper to the side of an output part while providing a clearance between the point end of the transmission rod and the valve rod, fixing a valve plate, at a normal temperature and bringing the both rods into contact only at a high temperature. CONSTITUTION:In an output side, a valve rod 32, fixing a valve plate 31, is pressed by a spring 33 to a valve stopper 34 in normal temperature operation. While in an input side, a seat member 46 is provided in the point end of a transmission rod 45 interlocking to a thermostat 43, and a clearance, being provided between the member 46 and the valve rod 32, causes the both members to generate no wearing. Next, if a cooling water temperature rises, the transmission rod 45 moves by action of the thermostat 43 in the left direction in the drawing to forcedly attach the seat member 46 to the valve rod 32, and the valve plate 31 also moves in the left direction in the drawing to open a return hole 24. That is, the valve rod 32 and the seat member 46, which are brought into contact only at a high temperature, substantially reduce wearing.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a viscous fluid coupling device, and more particularly, to a temperature-sensitive viscous fluid coupling device that controls output torque transmission in response to temperature changes. It relates to a fluid coupling device and is generally used as a cooling fan device for an automobile engine.

(Prior art) As a prior art related to the present invention, for example,
The one described in Publication No. 013 is already known.

The device disclosed in this publication includes an input member that is driven by an engine via a pulley and has a rotor thereon, an output member that is rotatably supported on the input member, and an output member that is fixed to the output member and has a rotor thereon. a partition plate that separates the internal space of the member into a storage chamber for storing viscous fluid and a working chamber for accommodating the rotor; a return hole formed in the partition plate for circulating the viscous fluid from the storage chamber to the working chamber; A valve plate fixed to the output member side to control the opening and closing of the return hole, a bellows as a temperature sensing means for detecting the temperature of the cooling water in the water pump, and a valve plate that moves in the axial direction within the input member in conjunction with the bellows. A transmission rod is provided, and the valve plate operatively connected to the transmission rod moves in the axial direction to control opening and closing of the return hole.

(Problems to be Solved by the Invention) However, in the above-described conventional device, a transmission rod that moves in the axial direction in conjunction with the temperature sensing means is disposed on the input member side, and a valve that controls opening and closing of the return hole. A plate is arranged on the output member side.

Therefore, at some point in the process of transmitting the displacement of the transmission rod to the valve plate, the relative rotation of both members (-number of rotations on the manually operated member side)
In the conventional device described above, the transmission rod on the output member side is brought into contact with the transmission rod on the input member side by the biasing force of a spring, and the two rods are slid together. By moving the shaft, the relative rotation is relieved.

Therefore, sliding wear occurs on the contact surfaces of both rods, and as this wear increases, an error occurs in the amount of displacement of the valve plate. As a result, there is a problem in that the operation control of the device deviates from the initial setting, or in the worst case, the rod member is damaged, resulting in loss of control and loss of engine cooling function.

Therefore, the technical object of the present invention is to reduce the amount of wear on the contact surface of the rod.

[Structure of the invention]

(Means to solve the problem) The technical measures taken to solve the above technical problem are:
A valve stopper is fixed on the output member side, and the valve plate is held by the valve stopper so that a gap is created between the tip of the transmission rod and the valve rod that fixes the valve plate only at a non-operating temperature of the temperature sensing means. That's true.

(Function) The transmission rod disposed on the input member side is moved in the axial direction by the driving force of the temperature sensing means when the temperature is high, and the movement of the transmission rod displaces the valve plate in the axial direction to open the return hole. During normal operation of the engine (when the engine cooling water temperature is low), the transmission rod on the input member side and the valve rod fixed to the valve plate on the output member side are held apart by a valve stopper, and both The rod member does not slide.

Generally, the state in which the temperature of the engine coolant is high and the cooling fan is rotated at high speed, that is, the state in which the torque transmission force of the viscous fluid joint is large, is about 10 to 20% of the average total running.
According to the invention, the sliding rate of both rod members is significantly reduced. In addition, since the cooling fan operates at low speed during normal engine operation, the relative rotation between the input and output members is large, and considering that the cooling fan rotates at high speed and the relative rotation is small at high temperatures, the relative rotation is small. The effect of the present invention that the transmission rod and the valve rod slide only when
It is clear that the rate is greater than the above rate (10-30%).

(Example) An example embodying the technical means of the present invention will be described below with reference to the accompanying drawings.

The viscous fluid coupling device 10 shown in FIG. 1 has a rotating shaft 12 as an input member that receives the driving force of an engine via a pulley 11, and a casing 14 is rotatably mounted on the shaft 12 via a bearing 13. A rotor 15 is integrally connected to the left end of the shaft 12 in the drawing. A cover 16 is fixed onto the casing 14 via a sealing O-ring 17 so as to form an internal space, and a partition plate 18 fixed to the cover 16 allows the internal space between the casing 14 and the cover 16 to be kept free of viscous fluid. The rotor 15 is separated into a storage chamber 19 in which the rotor 15 is stored and an operating chamber 20 in which the rotor 15 is housed. A first torque transmission surface 21 formed of a known labyrinth groove is formed on the opposing surface of the rotor 15 and the casing 14, while a first torque transmission surface 21 formed of a well-known labyrinth groove is formed on the opposing surface of the rotor 15 and the cover 16. 2 torque transmission surfaces 22 are formed. Storage room 1 is located on the partition plate 18.
As a passage for circulating the viscous fluid in 8 to the working chamber 20,
A first return hole 23 is provided on the outer circumferential side in the radial direction, and a second return hole 2 is provided on the inner circumferential side.
4 are formed respectively, and the first
) A passage 25 is formed in the rotor 15 so that a viscous fluid can be fed to the torque transmission surface 21. Further, a pump mechanism is formed by a pump protrusion 27 formed on the outer peripheral side of the rotor 15 and a pump hole 28, and the rotor 15 and the partition plate 18
When relative rotation occurs between the two, the viscous fluid in the working chamber 20 is fed to the storage chamber 19 by the action of the pump mechanism.

A spiral bimetal 29 that is activated by detecting the air temperature passing through the radiator is attached to the front surface of the cover 16, and the outer end of the bimetal 29 is fixed to the cover 16, while the inner end thereof is rotatable to the cover 16. It is fixed to a rod 30 attached to.

A valve plate 31 disposed on the storage chamber 19 side on the partition plate 18 is fixed at its axial center to a valve rod 32 screwed to a rod 30 as shown in FIG. That is, in conjunction with the bimetal 29, the valve plate 31 rotates on the partition plate 18 to control opening and closing of the first return hole 23.

The valve plate 31 is always urged in a direction to close the second return hole 24 (toward the right in the figure) by a spring 33 whose one end is locked to the flange portion 30a of the rod 30.

The valve plate 31 is axially displaced by a thermostat, which will be described later, to control opening and closing of the second return hole 24. cover 1
The valve stopper 34 fixed to the valve plate 31 holds the pulp rod 32 integrated with the valve plate 31, and the valve stopper 34 restricts the movement of the pulp rod 32 to the right in the drawing.

Now, the water pump 35 used for circulating engine cooling water has a pump body 36 fixed to a stationary part of the engine, and a rotary shaft 3 is disposed within the body 36.
7 is rotatably arranged.

The rotating shaft 37 is integrally connected to the rotating shaft 12 of the viscous fluid coupling device 10 and similarly receives the driving force of the engine. An impeller section 39 of a pump rotor 38 fixed on the shaft 37 supplies engine cooling water from the radiator to a discharge passage 41 that flows into a vortex chamber 40 in the body 36 . Drive unit 3 of shaft 37 of cooling water in vortex chamber 40
Sealing to the side 7a is performed by a well-known mechanical seal 42. A thermostat 43 that is activated by detecting the cooling water temperature in the vortex chamber 40 is attached to the right end of the shaft 37 in the drawing, and a first transmission rod 44 that is linked to the thermostat 43 is movable in the axial direction into a through hole in the shaft 37. will be placed in A second transmission rod 45 coupled to the first transmission rod 44 is accommodated in the shirt 12 so as to be movable in the axial direction, and a sheet member 46 fixed to the left end of the second transmission rod 45 in the drawing comes into contact with the pulp rod 32. and is configured to drive the valve plate 31 in the axial direction.

Next, the operation of the viscous fluid coupling device having the above configuration will be explained. When the air temperature passing through the radiator reaches the first predetermined temperature
(for example, 70°C), the valve plate 31 is in a position where the first return hole 23 and the second return hole are respectively closed, and the amount of viscous fluid in the working chamber 20 is minimized, and the cover (output The rotation of the fan attached to the member) 16 is maintained at a low speed (OFF state). Next, when the temperature rises and the air temperature passing through the radiator reaches the first predetermined temperature T1, the valve plate 31, which is linked to the spiral bimetal 29 that detects the air temperature and operates, opens the first return hole 23, and as a result, The viscous fluid is supplied from the storage chamber 19 through the first return hole 23 to the second torque transmission surface 22 in the working chamber 20, and the fan rotation is maintained at a medium speed (MIDDLE state). The temperature further increases, and the cooling water temperature in the vortex chamber 40 of the water pump 35 reaches a second predetermined temperature T higher than the above-mentioned body 1 predetermined temperature T1.
2 (for example, 95°C, where T I < T 2), the thermostat 43 detects the cooling water temperature, extends in the axial direction, and moves the first transmission rod 44 interlocked with the thermostat 43 to the left in the figure. let Therefore, the second transmission rod 45 connected to the first transmission rod 44 similarly moves to the left in the figure, and the valve rod 32, which is integral with the valve plate 31, is moved in the axial direction by the biasing force of the spring 33. That is, the valve plate 31 moves away from the partition plate 18 to open the second return hole 24, so that the viscous fluid flows from the storage chamber 19 through the second return hole 24 and the passage 25 passing through the rotor 15 to the first torque transmission surface. Also supplied to 21,
Fan rotation is maintained at high speed (ON state).

Here, in the OFF state and the ON state, a gap is maintained between the valve rod 32 and the seat member 46 due to the action of the valve stopper 34, as shown in FIG. 2, and no sliding wear occurs. No (position ■ in Figure 2). Then, only in the ON state, the sheet member 46 is displaced and slid to the position (■). The amount of wear can be further reduced by applying surface treatment (for example, induction hardening, carburizing and hardening, etc.) to the contact surfaces of the seat member 46 and the valve rod 32 to improve surface hardness and lubricity. The decrease can be measured.

〔Effect of the invention〕

Another method for reducing the amount of wear on the contact surfaces between the transmission rod on the input member side and the valve rod on the output member side is as follows:
As described in Japanese Utility Model Application Laid-Open No. 56-127430, there is a means for escaping the relative rotation by using magnetic bodies that repel each other. Regarding this means, the present invention has the following specific effects.

That is, as shown in FIG. 2, the valve rod 32 that fixes the valve putty 31 is pressed against the valve stopper 34 by the spring 33 during normal operation (at low temperatures below T2), and is pressed against the valve stopper 34 at high temperatures (at temperatures above T2). ), the valve plate is pressed against the seat member 46, thus preventing the valve plate from malfunctioning due to external vibrations from the engine or the like.

However, in the above cited example, the valve plate is held in a floating state by the spring and magnetic force, so that the valve plate easily swings due to engine vibration, which tends to cause malfunction.

Further, in the present invention, the relative positional relationship between the valve plate 31 and the partition plate 18 is fixed by the valve stopper 34, and sealing performance for closing the return hole is ensured.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a viscous fluid coupling device according to the present invention, FIG. 2 is an enlarged view of the main parts in FIG. 1,
FIG. 3 is a characteristic diagram showing the operation of the viscous fluid coupling device of FIG. 10---Viscous fluid coupling device, 12...Rotating shaft, 14...Casing, 15...Rotor, 16...
・Cover, 18... Partition plate, 19... Storage room, 20
... Working chamber, 23... First return hole, 24... Second
Return hole, 31... Valve plate, 32... Valve rod, 34... Valve stopper, 35... Water pump, 40... Vortex chamber, 43... Thermostat 44.45... Transmission rod

Claims (1)

[Claims] an input member driven by an engine and having a rotor thereon; an output member rotatably supported on the input member; and a storage chamber fixed to the output member and storing a viscous fluid in an internal space of the output member. a partition plate that separates the rotor into a working chamber; a return hole means formed in the partition plate for circulating viscous fluid from the storage chamber to the working chamber; and a return hole means fixed to the output member side. The valve plate includes a valve plate that controls opening and closing, and a transmission rod that moves in the axial direction within the input member in conjunction with a temperature sensing means that detects the water temperature in the vortex chamber of the water pump. In a viscous fluid coupling device in which a valve plate moves in the axial direction to control opening and closing of the return hole means, a valve stopper is fixed to the output member side, and the transmission rod is closed only in a non-operating temperature range of the temperature sensing means. A viscous fluid coupling device, wherein the valve plate is held by the valve stopper so that a gap is created between the tip and a valve rod that fixes the valve plate.