JPH0234422Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention relates to an engine water temperature detection device, and particularly relates to an improvement in its mounting position.

<Prior Art> As is well known, for example, in a fuel injection engine, the air-fuel ratio and ignition timing are controlled in accordance with the combustion form in the combustion chamber, and in engines equipped with an EGR device, the combustion form is similarly controlled. Let me deal with it
Controls the amount of EGR.

As one of the factors that reflect the combustion form used in this type of control, the temperature of the cooling water that cools the combustion chamber has traditionally been used.
An example is shown in Publication No.-30319.

The water temperature detection device disclosed in the same publication measures the cooling water temperature by installing a water temperature sensor protruding inside a water jacket provided on the cylinder lock side.

However, the water temperature detection device having such a configuration has the following problems.

<<Problems to be solved by the invention>> In other words, the water temperature detection device disclosed in the above publication measures the cooling water temperature in the water jacket on the side of the cylinder block, which is located quite far away from the combustion chamber provided in the head of the cylinder. However, it was difficult to quickly detect the combustion form. In order to quickly detect the combustion mode, it seems to be a good idea to install a water temperature sensor on the water jacket on the cylinder head side, but installing it on the cylinder head side has the following problems.

First of all, on the cylinder head side, especially in recent years,
In DOHC and SOHC engines, the camshaft and valve gear are arranged in a complicated manner, making it difficult to secure installation space for the water temperature sensor.Even if space could be secured, the head structure would be complicated, and the output signal of the water temperature sensor would be difficult to secure. The cord to take it out will be soaked in oil.

Further, when the water temperature sensor is provided protruding into the water jacket on the cylinder head side, there is also a problem in that this increases the flow resistance of the cooling water circulating in the jacket.

This idea was created in view of these problems, and its purpose is to improve combustion efficiency without complicating the cylinder head or affecting the flow of cooling water in the water jacket. An object of the present invention is to provide an engine water temperature detection device that can quickly obtain information corresponding to the configuration.

<Means for Solving the Problems> In order to achieve the above object, the engine water temperature detection device of this invention is located on the downstream side of the water jacket of the cylinder head, and detects the cooling water in the water jacket. A chamber is provided adjacent to a side wall of the water jacket substantially parallel to the water flow direction and having a cooling water inlet formed in the side wall so as to communicate with the water jacket, and in this chamber, the water jacket is connected to the water jacket. The temperature sensing part of the water temperature sensor was located downstream from the center of the cooling water intake in the direction of flow of the cooling water.

<<Operation>> According to the engine water temperature detection device configured as described above,
The temperature-sensing part of the water temperature sensor is located in a chamber provided downstream of the water jacket of the cylinder head, adjacent to the cylinder head, and in the center of the intake port in the flow direction of the cooling water flow of the water jacket. Due to its downstream position, the temperature of the cooling water flow itself of the cylinder head in which the combustion chamber is provided can be detected without increasing the resistance of the cooling water flow flowing into the water jacket.

<<Embodiments>> Hereinafter, preferred embodiments of this invention will be described in detail with reference to the accompanying drawings.

1 and 2 show an embodiment of an engine water temperature detection device according to this invention.

FIG. 1 is an overall view schematically showing the installation state of the water temperature detection device, and this embodiment illustrates the case where it is applied to an in-line four-cylinder engine.

A water jacket 12 is provided in the cylinder head 10 of the engine so as to surround the outer periphery of a combustion chamber (not shown).
A water pump 18 provided in the main passage 16 causes the cooling water inside the jacket to flow along a circulation path as shown by the solid arrow in FIG. 1, and a main cooling water flow A is formed inside the water jacket 12. be done.

Further, the water jacket 12 and the water pump 18 are connected by a sub passage 20, and a heater 22 is provided at an intermediate position of the sub passage 20.
When the heater 22 is started, a portion of the main cooling water flow A is divided to form a branched circulation path shown by dotted arrows in FIG.

Furthermore, a thermostat 24 and a bypass passage 26 that bypasses the main passage 16 are provided at the cooling water outlet from the water jacket 12, so that when the temperature of the cooling water is lower than the set temperature, the cooling water is turned off. Water is passed through the bypass passage 26 to the water pump 1
8 and prevents it from circulating to the radiator 14 side.

An intake manifold 30 having four intake passages 28a to 28d is fixed to one side of the cylinder head 10 via a mounting flange 32, and a water temperature detection device 34 connects the heater 22 and the water jacket 12. It is provided integrally with the intake manifold 30 at a branch portion of the sub passage 16 that connects the intake manifold 30 with the intake manifold 30.

The water temperature detection device 34 is located at the first position of the intake manifold 30, as shown in FIG.
It is comprised of a chamber 36 protruding from the outer surface of a mounting flange 32 between the cylinder intake passage 28a and the second cylinder passage 28b, and a water temperature sensor 38 installed within the chamber 36.

The chamber 36 is located on the downstream side of the main cooling water flow A in the water jacket 12 of the cylinder head 10, and the water jacket 12 is an elongated hole bored in the mounting flange 32 along the flow direction of the main cooling water flow A. They are communicated via a cooling water intake port 40.

Further, the water temperature sensor 38 is located at a central portion of the intake port 40 in the flow direction of the main cooling water flow A of the chamber 36 so that its temperature sensing portion 42 comes into contact with the main flow of the cooling water flow flowing into the chamber 36 from the intake port 40. Packing 46 to the boss 44 located further downstream
It is attached by screwing a nut 48 through the middle.

Furthermore, the outer surface of the chamber 36 is provided with an outlet 50 that faces the cooling water intake 40, and the intake 40 and the outlet 50 are spaced apart in the horizontal direction so that their cross sections do not overlap. The temperature sensing portion 42 of the water temperature sensor 38 is formed at the intake port 40 and the outlet port 50.
It is slightly deviated to the side with respect to the flow line of the cooling water that connects the A heater 22 is provided at the outlet 50.
A sub passage 20 communicating with is connected.

In the water temperature detection device 34 configured as described above,
When the heater 22 is operating, a part of the main cooling water flow A in the water jacket 12 is branched off and flows into the chamber 36 through the intake port 40, where it stagnates and falls slightly within the chamber 36. , outlet 50
It reaches the heater 22 through.

Furthermore, when the heater 22 is not in operation, a part of the main cooling water A in the water jacket 12 is branched off and flows into the chamber 36 through the intake port 40 and comes into contact with the temperature sensing part 42 of the water temperature sensor 38. The water becomes such a turbulent flow that it stagnates in the chamber 36 for a while, and then flows out into the water jacket 12 from the intake port 40 again.

During stagnation, the temperature of the cooling water is detected by the water temperature sensor 38. Since it is introduced in

Further, the temperature sensing portion 42 of the water temperature sensor 38 is located on the downstream side of the cooling water flowing into the chamber 36 and is slightly offset from the water flow line connecting the intake port 40 and the outlet port 50 within the chamber 36. Therefore, the temperature of the cooling water can be sufficiently measured even when the heater 22 is in operation or not, and there is no resistance to the cooling water flowing to the heater 22 side.

Furthermore, since the water temperature sensor 38 is housed in a chamber 36 that is integrally provided in the intake manifold 30 adjacent to the water jacket 12, the cylinder head 10 can be easily operated without complicating the cylinder head 10.
In addition, the main cooling water flow A in the water jacket 12
It also does not increase distribution resistance.

In the above embodiment, the chamber 36 housing the water temperature sensor 38 is formed integrally with the intake manifold 30 and is connected to the sub passage 20 for the heater 22. However, the chamber 36 is not necessarily integral with the manifold 30. It is not necessary to do so, and it may be provided separately from the sub passage 20 for the heater 22.

Further, the chamber 36 is connected to the water jacket 12.
It may be combined with a passage of a water-cooled water cooler from which a portion of the cooling water is branched and taken out.

<<Effects of the invention>> As described above in detail in the embodiments, the engine water temperature detection device according to the invention can reduce the flow resistance of the main cooling water flow in the water jacket without increasing the flow resistance of the main cooling water flow, and It is possible to measure temperatures extremely close to the water temperature around the combustion chamber without complicating the head or valve mechanism.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the installed state of the device of the present invention, Figure 2
Figure 2a is a perspective view of the intake manifold to which the device is attached, Figure 2b is a cross-sectional view taken from the side of Figure 2a, and Figure 2c is a cross-sectional view taken from the side of Figure 2a. 10...Cylinder head, 12...Water jacket, 36...Chamber, 38...Water temperature sensor, 40...Intake port, 42...Temperature sensing section.

Claims (1)

[Scope of utility model registration request] A cooling water inlet is formed on the downstream side of the water jacket of the cylinder head, adjacent to a side wall of the water jacket substantially parallel to the flow direction of the cooling water in the water jacket, and forming a cooling water inlet in the side wall. A chamber communicating with the water jacket is provided, and a temperature sensing part of a water temperature sensor is located in the chamber downstream from the center of the cooling water intake in the direction of flow of the cooling water in the water jacket. An engine water temperature detection device characterized by: