JPS5882013A - Controller for temperature of cooling liquid of internal-combustion engine - Google Patents

Abstract

PURPOSE:To eliminate the need for a sealing member, and to operate a control section, which controls a thermostat in response to the state of operation of the internal-combustion engine and controls the temperature of the cooling liquid, positively by connecting the control section to the thermostat in a cooling liquid path. CONSTITUTION:The thermostat 3 is positioned between a water outlet 22 and a water outlet housing 23. The control section 25 consists of a stopper 35 connected to a negative pressure introducing pipe 34, a bellows 36, which is set up around the stopper, and a flange section 33, which is connected to the lower end of the bellows 36 and has a control shaft 26, and is disposed into the water outlet housing 23. The control shaft 26 is slid in a rubber member 27 mounted into the temperature sensing section 24 of the thermostat 3, changes the volume of space 40 in response to the negative pressure of a suction pipe, and can adjust the temperature of the valve opening of the thermostat 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coolant temperature control device for an internal combustion engine, and in particular:
A control device is provided within the coolant passage.

Various coolant temperature control devices that control valve opening humidity according to the load of an internal combustion engine have been proposed in the past.

FIG. 1 shows this type of control device disclosed in Japanese Utility Model Application Publication No. 44'-1412722, in which a wax-type thermostat 3 is sandwiched between a water outlet provided in the engine body and a water outlet housing 2. has been done. This thermostat J has a container shape f
It has an M section and a piston j that slides up and down in the temperature sensing section.The temperature sensing section is charged with solid wax and elastic rubber, and a part of the screw F>j is constructed so that the upward biasing force is suppressed by the operation of the control piece B, which will be described later.When the wax partially expands, the head of the piston j is pushed by the control piece B due to the pressure generated. As long as it is restrained, the temperature sensing portion is pushed downward. 7 is a valve member provided on the outside of the temperature sensing part DA, and when the thermostat 3 is not activated, the spring force of the spring t
The valve member 7 is biased toward the fixed valve seat to close the coolant passage 10. The control piece 4 is attached to the diaphragm 12 of the control piece actuating diaphragm device //, and the diaphragm Device 1/
is attached to the water outlet housing via a seal member /3. The upper chamber of the diaphragm device divided into upper and lower parts by the diaphragm 12 is a negative pressure chamber l.
#, and the lower part is an atmospheric chamber /j that communicates with the atmosphere. The negative pressure chamber l# is connected to a negative pressure source in the intake manifold (not shown) via a negative pressure delay valve/l, and the intake negative pressure is applied to the negative pressure chamber/11 according to engine load fluctuations.
guided by.

17 is a stopper provided at the top of negative pressure chamber l#;
The control end 4A restricts upward movement when sliding up and down along the inner surface of the guide member/1 of the thermostat J. 19 is a spring installed in the negative pressure chamber l#, and when the negative pressure introduced into the negative pressure chamber becomes small and approaches atmospheric pressure, the spring force causes the diaphragm 12 and the control piece t to move as shown in the figure. Return to position.

To explain the operation of the coolant temperature control device configured in this way, first, when 1Ii6 is loaded, the suction negative pressure in the intake manifold is relatively small and the diaphragm /2 is biased downward as shown in the figure. ,
The control piece 6 is kept in the position shown in the figure. Therefore, when the coolant temperature rises and the wax on the temperature sensing part melts and becomes tensile, the head end of the piston j immediately comes into contact with the end 4m of the control piece 6 and tries to extend upward. The biasing force exerted is restrained by the spring force of the spring 19. Therefore, the temperature-sensing part t of the mostat 3 is pushed downward against the spring force of the temperature-sensing part 3, and the valve member 7 provided around the temperature-sensing part 7 is pulled away from the valve seat 9, opening the valve. do. In other words, when the engine is under high load, the thermostat 3 opens the valve at a relatively early stage when the coolant temperature rises, so the coolant temperature is relatively low at the time when the valve starts opening. , for example, is maintained at around 70°C.

Next, when the engine is under low load, a relatively large suction negative pressure is introduced into the negative pressure chamber l#, so that the control piece ≦ is pulled upward together with the diaphragm 12 against the spring force of the spring 19. Therefore, due to the rise in coolant temperature, the temperature sensing part l
When the wax expands, first piston j starts to extend upward, but since the end 6A of control H6 is pulled upward, the piston j continues until the free end of piston j comes into contact with end ≦A. j continues to be distracted. After the piston j comes into contact with the control piece 6, the valve is opened by the thermostat J in the same manner as described above.

In other words, the temperature is kept relatively high compared to when the load is high.

However, in such a conventional coolant temperature control device for an internal combustion engine, the diaphragm device is disposed outside the water outlet housing, and the diaphragm device is located outside the water outlet housing and is connected to the thermostat provided in the coolant passage 10 and the control device. Piece 6
It is connected via A.

Furthermore, the seal member 13 provided around the control piece t that slides up and down prevents the coolant in the coolant passage 10 from leaking to the outside.

In this way, since the control piece ≦ slides in close contact with the sealing member 13, the outer circumferential surface of the control H6 and the sealing member 13 are worn, and the coolant may leak to the outside or one or one control piece 6 The stick or frictional force between the control H6 and the sealing member 13 makes the operation of the control H6 uncertain, making it difficult to operate in a sensitive manner to changes in the suction negative pressure.

Further, since the thermostat 3 cannot sufficiently control the coolant temperature, the solvent consumption rate in the low load region of the internal combustion ah cannot be sufficiently improved.

It is an object of the present invention to eliminate the above-mentioned drawbacks, and to install a thermostat that opens the valve depending on the coolant temperature and a control unit that controls the thermostat in response to the intake negative pressure of the internal combustion engine within the coolant passage of the internal combustion engine. An object of the present invention is to provide a coolant temperature control device for an internal combustion engine flash connected to the engine.

Hereinafter, the present invention will be explained in detail based on the drawings.

1 and 3 show an embodiment of the present invention, FIG. 2 shows a state under low load, and FIG. ts3 shows a state under high load. In Figure 2, l is water outlet n
and a water outlet housing n, and this thermostat l has a temperature sensing part xy@: 1. , A control shaft constituting an actuator as a control section B slides up and down inside the temperature sensing section H of the control section B. Wax I is filled between the rubber member 1 fitted on one end of the control shaft and the temperature sensing part main body 3. When the mostat l is not activated, the valve member l is held in place by the spring. Due to the spring force, it comes into close contact with the valve seat 3/, closing the coolant passage J2. A seven rung portion 33 having a surface orthogonal to the control shaft 1 is provided at the other end of the control shaft, and this seven rung portion 33 and
A spring I is interposed between the negative pressure introduction 9j'J# and a stopper 3j fixed to the water outlet housing B to form a negative pressure WIin by a-X' 74. Also, 1 is a guide that guides the control axis, ? M is a narrow surface of this guide 1, 〃 is a space formed between the rubber member 1 and the control shaft, and V is a seal.

In the coolant temperature control device for an internal combustion engine configured as described above, when the coolant temperature reaches the wax melting point, the wax d melts and expands, and moves upward through the control shaft via the rubber member l. When the load is low, the seventh rung 33 is in contact with the stopper 3j as shown in FIG. 2, and the seventh rung 33 and the stopper 3j are in contact with each other as shown in FIG. Since the spring force of spring 1 is set to a predetermined value even when the load is high and the control shaft is held at the position shown in Fig. 1 or 3, the temperature sensing The valve member J and the valve seat 3/ are separated from each other, and the thermostat 1
Open the valve.

That is, as shown in Fig. 2, when the engine is operating at a low load, the suction negative pressure in the negative pressure chamber increases, so that the seven rungs 33 of the control shaft S resist the spring force of the spring N. The control shaft is placed in an upwardly displaced state, and a space 9 is created between the foot of the control shaft and the rubber member 1 fitted to the control shaft. Because this space remains, even if the coolant temperature rises, the expansion of the wax 1 is absorbed into the space 9 via the rubber member 1, and no compressive force is transmitted to the control shaft. Therefore, the temperature of the coolant until the wax 1 expands and completely eliminates the space V is irrelevant to the control operation (i.e., the temperature of the coolant is 0). Since the valve opening temperature of the thermostat 1 can be kept high and constant.

Next, as shown in FIG. 3, when the engine is operating under high load, the suction negative pressure in the negative pressure chamber I decreases and approaches atmospheric pressure, so that the seventh rung part 33 is activated by the spring force of the spring n. Guided by? The end face J? It is displaced downward until it comes into contact with A.

In this state, there is no space invasion, so when the coolant temperature rises and the wax d of the temperature sensing section 3 expands, this expansion force immediately acts as a force to push up the control shaft. That is, when the load is high, the thermostat 1 opens in response to a rise in coolant temperature, so the valve opening temperature of the thermostat 1 can be lowered.

In the coolant temperature control device configured in this way,
Since the control shaft for controlling the thermostat and the negative pressure chamber 31 are provided in the coolant passage 32, there is no need for the seal member 13 provided to prevent coolant leakage as in the conventional example. Since no friction or wear occurs between the member 13 and the control shaft, the control shaft operates reliably in response to the coolant temperature.

As described above, according to the present invention, since the thermostat and the control section for controlling the valve opening temperature are provided in the coolant passage of the internal combustion engine, the seal for preventing coolant leakage can be removed. This eliminates uncertainties caused by coolant leakage and frictional force between the control shaft and the seal, allowing accurate and reliable temperature control of the coolant, and improving fuel consumption, especially in low load areas. can be efficiently improved.

Further, according to the present invention, since the coolant temperature control device is provided in the coolant passage, the number of components is reduced.
Therefore, it goes without saying that the device can be made smaller and lighter, and the cost can be lowered.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of a conventional coolant temperature control device, Fig. 1 is a block diagram showing an example of the coolant temperature control device of the present invention in a low load state, and Fig. 3 is a block diagram showing an example of the coolant temperature control device of the present invention in a low load state. It is a block diagram shown in the state at the time of load. /...Water outlet 1 λ...Water out left housing, 3...Thermostat, D...Temperature sensing part,! ···piston,
4...Control piece, 4A...End part,'
7...Valve member, I...Spring, t...
Valve seat, 10...Cooling liquid passage, //...Diaphragm device, 12...Diaphragm /3...Seal member, /#...Negative pressure chamber, lj...Atmospheric chamber, 16.・
・Negative pressure delay valve, /7... Stopper, /1... Guide member, 19... Spring, 1... Thermostat, n.
...Water outlet, n...Water outlet housing, 2nd...Temperature sensing part, 3A.
・・Temperature sensing unit main body, B・control unit, M・・
Control axis, 1... = f glL X... Wax, ? ...Valve member, 30...Spring, J
/...Valve seat, 32...Cooling liquid passage, 3
3...7 rung section, 3...negative pressure introduction pipe,...
Stopper, 36...Bellows, n...Spring, 3g.
...Negative pressure chamber, 1...Guide, nA...End face, V...Empty f&l], Dato...Seal. Patent applicant: Nissan Motor Co., Ltd. @Figure 1 Figure 2

Claims (1)

[Claims] 1) A cooling device having a thermostat that opens a valve depending on the temperature of the coolant in the coolant passage, and a control section that controls the thermostat to control the temperature of the coolant depending on the operating state of the internal combustion engine. A coolant temperature control device for an internal combustion engine, characterized in that the thermostat and the control section are connected in the coolant passage, and a coolant temperature control device for an internal combustion engine according to claim 1. In the coolant temperature control device, the control shaft of the thermostat is connected to a base that is positioned according to the operating state,
A coolant temperature control device for an internal combustion engine, characterized in that the length of the control shaft in the thermostat is configured to change in accordance with operating conditions.