JPS5928778B2 - Fluid type fan coupling device for cooling automobile engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally relates to a fluid type fan coupling device often used to control fan rotation for cooling internal combustion engines of automobiles, etc., and in particular to a temperature-sensitive control mechanism that controls fan rotation according to changes in ambient temperature. The synergistic effect between this and the speed-sensitive control mechanism that controls the rotation of the output side fan based on changes in the rotational speed (rotations per unit time) of the input side drive spindle allows for a finely tuned cooling air volume that meets the needs of engine cooling. The present invention relates to a novel temperature-sensitive and speed-sensitive hydraulic fan coupling device that is capable of controlling.

A fluid for transmitting rotational force is interposed between the rotary drive side disk connected to the drive shaft and the inner wall of the driven side coupling with fan blades attached around the outside, and the rotational force is transferred from the drive side to the driven side due to the viscosity of the fluid. As a cooling fluid type fan coupling device that transmits the A so-called temperature-sensitive hydraulic fan coupling device is known, which controls the amount of fluid in the torque transmission chamber by opening and closing the inflow hole, thereby controlling the fan rotation speed.

However, as shown by the virtual line in Figure 4, the characteristics of these conventional temperature-sensitive coupling devices are that the fan rotation speed on the driven side remains almost constant when the external ambient temperature after passing through the radiator reaches around 60°C. It is merely a matter of maintaining it.

These approximately constant control rotational speeds are set at a relatively high value of 3000 to 4000 RPM in consideration of a wide variety of usage conditions during winter, summer, and engine running.

For this reason, under operating conditions that do not require a large amount of cooling air from the fan rotation, i.e., during low temperature and high speed, low temperature and low speed, high temperature and high speed during winter, and during normal driving, the engine is generally overcooled and the engine is not in good condition. Not only does this tend to impede the operating condition, but unnecessary horsepower and fuel consumption are unavoidable due to unnecessary fan drive, and fan noise cannot be sufficiently reduced.

Therefore, an object of the present invention is to provide a speed-sensitive control mechanism that controls the fan rotation speed in response to the drive side rotation speed (speed) in addition to the temperature-sensitive operation mechanism, and as a synergistic effect of these two mechanisms, the drive section side In the high rotation speed range of the drive section, the fan rotation speed is reduced regardless of whether the external ambient temperature is high or low, and in the low rotation speed range of the drive part side, the fan rotation speed is increased only when the external ambient temperature is high. It is an object of the present invention to provide a novel fluid type fan coupling device which can simultaneously solve the above-mentioned drawbacks of the conventional technology by lowering the temperature at low temperatures.

Hereinafter, the present invention will be described in detail with reference to the drawings. Reference numeral 1 denotes a rotating main shaft as a drive unit side, 2 a rotary main shaft supported by the rotating main shaft 1 via a bearing B, and a fan blade F attached to the outer periphery. The driving side case 3 is a case cover that is sealed and connected to the front outer circumference of the case 2 to form a sealed case.

The sealed case is partitioned into an oil reservoir chamber 6 and a torque transmission chamber 4 by a partition plate 5 through which an internal fluid (oil, etc.) inflow hole 5' is inserted. A fluid circulation outflow path 7 leading from the side to the oil reservoir chamber 6 side is provided.

8 has one end riveted to the oil reservoir chamber 6 side of the dividing plate 5 and the other end, or by an external signal set at a predetermined external ambient temperature.
A plate-shaped valve member configured to elastically open and close the inflow hole 5' is used, and in the example shown in the figure, the plate-shaped valve member 8 is a band serving as a temperature sensor whose both ends are fixed to the outer front surface of the case cover 3. A connecting rod 10 that slides following the curved deformation of the plate-shaped bimetal 9
The inflow hole 5' is opened and closed in accordance with the bending deformation of the bimetal due to the predetermined temperature change.When the ambient temperature exceeds a predetermined value, the inflow hole 5' is opened to allow fluid to pass through, and the inflow hole 5' is opened and closed to allow fluid to pass through. When the value falls below this value, the inflow hole 5' is closed.

At the tip of the rotating main shaft 1 protruding inside the sealed cage, there is a support wall for the rotating main shaft 1 along the inner circumferential wall of the case 2, and a front wall extending along the inner circumferential wall of the dividing plate 5 and having an open center. A drive disk 11 formed of a frame-like structure with a rectangular cross section and an annular wall 11'' is fixedly installed. A torque transmission gap 4' is formed.

An outflow hole 11' from the support wall IC and the auxiliary oil reservoir chamber 12 to the torque transmission gap 4' is provided through the support wall IC for the rotating main shaft, and near the outflow hole 11' there is a predetermined rotation speed of the 1st drive unit. A centrifugal valve (2) is provided which opens and closes the outflow hole 11' by centrifugal force depending on the speed.

For example, as shown in FIG. 2, this centrifugal valve (2) has one end pivotally supported by the bottom wall of the disk 11, and the other end supported by a spring 13, so that the rotationally driven disk 11 is rotated at a predetermined rotational speed. When the rotation speed of the disk exceeds a predetermined number of rotations, it closes the outflow hole 11' while sliding radially outward along the bottom wall surface against the spring 13 due to centrifugal force.On the other hand, when the rotation of the disk decreases below a predetermined rotation speed, It is configured to open the outflow hole 11'.

A spiral forced oil feed groove 14 is provided on the outer peripheral surface of the side wall of the rotating disk 11 facing the torque transmission gap 4', and the fluid is guided along the groove to the circulation outflow path γ side of the case. ing.

Furthermore, reference numeral 15 designates a weir provided at the edge of the opening of the circulation outflow passage 7 in the inner circumferential wall of the case 2 or at the recessed part thereof, facing the outer circumferential wall surface of the drive disk, to drain the fluid collected at the entrance of the outflow passage 7. It has a pump function for feeding into the outflow path 7.

Incidentally, an intrusion prevention means is provided to prevent the fluid in the auxiliary oil reservoir chamber 12 from entering between the front annular wall 11'' of the drive disk and the dividing plate 5.

In the example shown in FIG. 1, as an intrusion prevention means, a dish-shaped shielding member 16 having an opening periphery is provided on the dividing plate 5, and the opening periphery covers the tip of the annular wall 11'' of the disk. .

However, the backflow prevention means is not limited to such a configuration. For example, the pipe body communicating from the inflow hole 5' is connected to the outflow hole 1 of the auxiliary oil reservoir chamber 12.
The object can also be achieved by a configuration projecting in the 1' direction.

In the drawings, arrows in FIG. 1 indicate the flow of fluid such as oil, and arrows in FIGS. 2 and 3 indicate the direction of rotation of the drive disk 11.

Further, in the embodiment shown in FIG. 1, the side walls of the case 2 and the rotary drive disk 11 are formed parallel to the rotation main shaft 1, but the present invention is not limited to this, and the side walls of both members are formed parallel to the fluid flow direction. In other words, it includes a configuration in which the diameter is expanded in a trumpet shape toward the case cover side, and when formed in this way, the fluid flow is smoother, and the fan rotation control can more quickly respond to changes in usage conditions. becomes possible.

As described above, the device of the present invention has a temperature-sensitive operating mechanism that opens and closes the inflow hole 5' of the dividing plate 5 according to changes in external ambient temperature, and also operates via a centrifugal valve (2) according to changes in the rotational speed of the rotating main shaft. Since a temperature-sensitive operating mechanism is provided to open and close the outflow hole 11' of the disc 11, the inflow hole 5' is opened when the external ambient temperature is higher than a predetermined temperature, and when the rotation speed of the disk is below a predetermined value. Only when the outflow hole 11' is open (high temperature and low speed), the fluid (oil, etc.) flows out to the torque transmission gap side, increasing the effective contact area of the fluid amount in the torque transmission gap, and thereby the fan In addition to increasing the torque transmission for rotation, even if the external ambient temperature is above a predetermined temperature and the inlet hole 5' is open, if the rotational speed of the drive disk is higher than the predetermined speed, the centrifugal valve will prevent the flow from flowing out. hole 11'
is closed, torque transmission is limited and fan speed is reduced.

Therefore, when the cooler is used during pitching or stopping in the summer, the torque transmission for fan rotation is increased only when the temperature is high and low speed, and sufficient cooling air is supplied. As a result, the fan rotation speed is reduced during normal driving or during winter when the amount of air blowing is not required, that is, during high-temperature high-speed operation, low-temperature high-speed operation, and low-temperature low-speed operation.

If the above relationship is shown as a control characteristic curve, A and A' in Fig. 4 are shown.
It is expressed as

That is, A shows the control characteristics of the device of the present invention in winter (at low temperatures and low speeds, low speeds and high speeds), and A′ shows the control characteristics of the device of the present invention in the summer when running uphill and when using a cooler while stopped (at high temperatures and low speeds). ) and the control characteristics during normal driving in summer (high temperature and high speed).In particular, it is a control characteristic curve showing the transition from high temperature and low speed to high temperature and high speed.

Incidentally, as described above, the virtual line is the control characteristic curve at high temperature by the conventional temperature-sensitive actuation type.

Since the present invention has the above-described structure and operation, it is possible to prevent the tendency of overcooling of the engine as a whole and maintain a good engine condition, and more effectively reduce the horsepower and fuel consumption required for driving the fan. In addition, it is extremely useful because various excellent effects such as being able to reduce fan noise associated with high speed can be achieved at the same time.

□ Brief description of the drawings Fig. 1 is a vertical sectional view of a fluid type fan coupling device for cooling an automobile engine showing one embodiment of the present invention, Fig. 2 is a diagram illustrating the installation and operation of the centrifugal valve in Fig. 1, and Fig. FIG. 3 is a cross-sectional view taken along the line A--A in FIG. 1 showing the weir section as a pump mechanism, and FIG. 4 is a comparative curve diagram showing the control characteristics of the device of the present invention and the conventional device.

1...Rotating main shaft, 5...Bunching plate, 11
... Drive disk, 11' ... Outflow hole, 11" ... Annular wall, 12 ... Auxiliary oil sump chamber, ■ ... centrifugal valve.

Claims (1)

[Scope of Claims] 1. A driven side sealed case is supported via a bearing on a rotating main shaft with a drive disk fixed to the tip, and a fan blade is fixed to the outer periphery. A dividing plate is used to divide the oil reservoir chamber into an oil reservoir chamber and a torque transmission chamber in which the drive disk is housed, and a dam is provided on a part of the inner circumferential wall of the sealed case side facing the outer circumferential wall surface of the drive disk where oil collects during rotation. In conjunction with this, an outflow path is formed that leads from the torque transmission chamber side to the oil reservoir chamber side, and when the external ambient temperature exceeds a set value, the inflow hole of the dividing plate is opened, and when it is below the set value, it is closed. A valve member is provided inside so as to be interlocked with the curvature deformation due to temperature change of the temperature sensing element provided on the front surface of the sealed case,
A fluid coupling device that controls torque transmission from the rotating main shaft side to the driven side of the sealed case by increasing or decreasing the effective contact area of the amount of oil in the torque transmission gap between the facing surfaces of the drive disk and the sealed case. In the drive disk 11
A support wall for the rotational main shaft along the inner circumferential wall of the case 2 on the side of the torque transmission chamber 4, which is partitioned into The torque transmission chamber 4 is formed with a frame-like structure with a rectangular cross section, and the auxiliary oil reservoir chamber 12 is formed inside the frame-like structure, and the torque generated between the outer circumferential wall surface of the drive disk 11 and the inner circumferential wall surface of the case 2. The transmission gap 4' is divided into a drive disk 11.
A fluid outflow hole 11' is provided through the support wall for the rotating main shaft, and a drive disk 11 is provided in the vicinity of the outflow hole 11'.
A speed-sensitive control valve mechanism is provided which opens the outflow hole 11' below a predetermined rotational speed and closes the outflow hole 11' with a centrifugal valve V when the rotational speed exceeds a predetermined rotational speed.
Between the front annular wall 11'' extending into the auxiliary oil reservoir chamber 12 from the inlet hole 5' provided in the dividing plate 5 radially inward from the tip of γ' and the dividing plate 5. 2. A fluid type fan coupling device for cooling an automobile engine, characterized in that a member is provided for preventing the intrusion of fluid. 2. In the fluid type fan coupling device according to claim 1, the drive disk 11 A fluid cooling type for automobiles, further characterized in that the outer peripheral wall surface and the inner peripheral wall surface of the case 2 facing the outer peripheral wall surface are configured such that the diameter thereof is expanded in a trumpet shape toward the oil reservoir chamber 6 side on the case cover 3 side. Fan coupling device. 3. The fluid type fan coupling device according to claim 1 or 2, characterized in that a spiral forced oil feeding groove is formed on the outer peripheral side wall surface of the drive disk 11. A fan coupling device for cooling an automobile engine.4 In the fluid type fan coupling device according to claim 3, the tip annular wall 11 of the drive disk 11
The member for preventing fluid from entering between the drive disk 11 and the partition plate 5 consists of a dish-shaped shielding member 16 formed to cover the tip of the front annular wall 11 on the drive disk 11 side at the opening periphery. A fan coupling device for cooling automobile engines featuring: 5. In the hydraulic fan coupling device according to claim 3, the front annular wall 11 of the drive disk 11
A member that prevents fluid from entering between the inflow hole 5 and the dividing plate 5
A fluid-type fan coupling device for cooling an automobile engine, characterized in that it is a pipe body projecting from the auxiliary oil reservoir chamber 12 toward the outflow hole 11'.