JPS6226585Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a water pump for an internal combustion engine.

Usually, an internal combustion engine is equipped with a water pump for circulating engine cooling water, and this water pump is rotated by a crankshaft in proportion to the rotational speed of the crankshaft. However, with such a water pump, even when the engine is cold and there is no need to circulate a large amount of cooling water, the water pump is forced to rotate at high speed with a large driving force, which not only results in a loss of engine horsepower, but also causes a loss in engine heat. There is a problem that it takes a long time to set up the machine.

To solve these problems, a pulley driven by a belt is connected to the water pump shaft via an electromagnetic clutch, and a water temperature sensor that detects the engine cooling water temperature is placed in the engine cooling water passage. A water pump is known in which operation of the water pump is stopped by disconnecting an electromagnetic clutch in response to an output signal from a sensor. (Refer to Japanese Patent Application Laid-open No. 136144/1983). However, using an electromagnetic clutch in this way not only requires space to install the electromagnetic clutch, but also has the problem of rising costs because the electromagnetic clutch itself is expensive and a control circuit is also required. .

The object of the present invention is to provide a water pump with a simple structure that does not require a special space for controlling the water pump and can be manufactured at low cost.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to the drawings, 1 is a water pump housing fixed to the machine body, 2 is a cooling water passage, and 3 is a water pump housing fixed to the machine body.
4 is a rotor fixed to the water pump shaft 3; 5 is an impeller casing rotatably mounted on the water pump shaft 3 via a bearing 6; Reference numeral 7 indicates a plurality of impellers attached to the outer periphery of the impeller casing 5, and when the impellers 7 rotate, cooling water flows in the cooling water passage 2 as shown by arrow A. The impeller casing 5 is composed of a disk-shaped first casing 8 and a cup-shaped second casing 9, which are firmly connected to each other by a coupling band 10. In the drawings, a viscous friction transmission section 11 having a labyrinth structure is formed between the right side wall surface of the rotor 4 and the left side wall surface of the first casing 8. Furthermore, a viscous fluid inflow chamber 12 is formed inside the viscous friction transmission section 11 in the radial direction, and a viscous fluid outflow path 1 is formed outside the viscous friction transmission section 11 in the radial direction.
3 is formed. A viscous fluid storage chamber 15 isolated by a partition plate 14 is formed in the second casing 9, and the viscous fluid outflow path 13 communicates with this viscous fluid storage chamber 15. A viscous fluid flow path chamber 16 is formed between the partition plate 14 and the rotor 4, and this viscous fluid flow path chamber 16 is connected to the opening 1 formed in the rotor 4 on the one hand.
7 to communicate with the viscous fluid inlet chamber 12, and on the other hand communicate with the viscous fluid storage chamber 15 via an opening 18 formed in the partition plate 14. A wax valve 19 is attached to the second casing 9, and this wax valve 19 is connected to a temperature sensing portion 20 disposed in the cooling water passage 2.
and an on-off valve 21 that controls opening and closing of the aperture 18.
A compression spring 22 is provided that always biases the on-off valve 21 toward the left.

When the engine cooling water temperature reaches a predetermined temperature or higher, the wax in the wax valve 19 expands, so the opening/closing valve 2
1 moves to the right against the compression spring 22, and as a result, the aperture 18 opens. At this time, the viscous fluid in the viscous fluid inflow chamber 12 reaches the viscous fluid outflow path 13 through the viscous friction transmission section 11 due to centrifugal force, and then moves through the viscous fluid storage chamber 15, the opening 18, and the viscous fluid flow path chamber. 16 and the opening 17 to circulate into the viscous fluid inlet chamber 12 again. When the viscous fluid is circulated in this manner, since the viscous fluid is always present in the viscous friction transmission section 11, a transmission torque is generated by shearing the viscous fluid between the rotor 4 and the first casing 8. As a result, the rotational torque of the rotor 4 is efficiently transmitted to the impeller casing 5, and thus the impeller casing 5 rotates together with the water pump shaft 3 at a high speed.

On the other hand, when the engine cooling water temperature is below a predetermined temperature, the on-off valve 21 closes the opening 18 as shown in the drawing, and therefore, the circulation of the viscous fluid is stopped at this time. In this way, after the viscous fluid in the viscous fluid flow path chamber 16 and the viscous fluid inflow chamber 12 passes through the viscous friction transmission section 11 due to centrifugal force, this viscous fluid is only accumulated in the viscous fluid storage chamber 15. Therefore, there is almost no viscous fluid in the viscous friction transmission section 11. As a result, when the engine cooling water temperature is low, almost no rotational torque of the rotor 4 is transmitted to the impeller casing 5, and thus the impeller 7 rotates at a much lower speed than the water pump shaft 3.

As described above, according to the present invention, the internal space of the impeller casing is used to provide a viscous friction transmission mechanism therein, and the wax valve attached to the impeller casing controls the circulation of viscous fluid. That is, in the present invention, the connection and disconnection mechanism between the water pump shaft and the impeller and its control device are all housed within the impeller casing, so there is no need to provide a separate space for installing the water pump control device. It has the advantage that it can be easily installed even if the space in the engine room is narrow.
Another advantage is that manufacturing costs can be reduced because no expensive electrical parts are required.

[Brief explanation of the drawing]

The figure is a side sectional view of a water pump according to the present invention. 2...Cooling water passage, 3...Water pump shaft,
4... Rotor, 5... Impeller casing, 7...
... Impeller, 11 ... Viscous friction transmission section, 19 ...
Wax valve.

Claims (1)

[Scope of utility model registration request] A rotor fixed on a water pump shaft in a cooling water passage; an impeller casing sealingly surrounding the rotor in the cooling water passage and rotatably mounted on the water pump shaft; The rotor and the inner wall surface of the impeller casing are arranged close to each other to form a viscous friction transmitting section between them, and a viscous fluid circulation path is formed in the impeller casing to reach the viscous friction transmitting section again via the viscous friction transmitting section. A wax valve that controls the opening and closing of the viscous fluid circulation path in response to the engine cooling water temperature is fixed to the impeller casing, and the wax valve shuts off the viscous fluid circulation path when the engine cooling water temperature is below a predetermined temperature. A water pump for internal combustion engines.