JPH0311703Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cooling water level alarm device for an automobile that is installed in a reserve tank of a radiator and issues an alarm when the water level in the reserve tank falls below a certain level.

Conventionally, this type of water level alarm device was installed downward from the cap on the top of the tank (for example, the device described in Japanese Patent Application Laid-Open No. 126627/1983).
It is known that the alarm device is installed upward from the bottom of the tank, but in the former case, the water level to be detected is below the tank, so it is necessary to extend the alarm device from the top of the tank to the bottom. Not only is it time-consuming, but the number of parts in the device increases, which is a factor that increases product costs.Also, in the latter case, the alarm device is screwed and fixed to the bottom of the tank, which makes it prone to leakage and reduces the reliability of the device. There was a flaw in it.

Therefore, the present invention involves inserting the sensor case together with a damper into a hole drilled at the bottom of the tank, and bonding and fixing the sensor case to the bottom of the tank in a watertight manner.
It is an object of the present invention to provide a cooling water level alarm device for an automobile that eliminates the above-mentioned drawbacks by inserting a sensor element into the sensor case from outside the tank.

Hereinafter, the present invention will be specifically explained based on an embodiment shown in the drawings.

As shown in FIG. 1, a reserve tank 1 of an automobile radiator has a hollow shape of a substantially rectangular parallelepiped, and can store cooling water 2 therein. A cap 3 is detachably provided at the top of the tank 1, and a water level alarm device 4 is provided at the bottom. Further, as shown in FIG. 2, a hole 1a is bored in the bottom of the tank 1, and a sensor case 5 of the alarm device 4 is fitted into the hole 1a. The sensor case 5 is a hollow body in which a hole 5b for inserting a sensor element 7 (described later) is formed, and the sensor case 5 has a three-stage small diameter cylindrical part 5c and a medium diameter cylindrical part 5e whose diameter becomes larger toward the bottom. ,
It is composed of a large diameter cylindrical part 5f, and further has an annular flange 5a projecting outward at the lower end of the large diameter cylindrical part 5f, and an annular flange 5a projecting upward at the closed end of the small diameter cylindrical part 5c. It has a protrusion 5d. The outer diameter of the large diameter cylindrical portion 5f is equal to the inner diameter d of the hole 1a of the tank.
This large diameter cylindrical portion 5f is substantially the same as the hole 1a.
It is designed to fit tightly. Furthermore, the flange 5a protrudes from the large diameter cylindrical portion 5f.
When the large-diameter cylindrical portion 5f is fitted into the hole 1a, it comes into close contact with the bottom of the tank, and the flange 5a and the tank 1 are bonded and fixed by means such as adhesive or welding at this contact surface. Therefore, the sensor case 5 is securely fixed to the tank 1, and the inside and outside of the tank 1 are sealed by the flange 5a. Further, as shown in detail in FIG. 3, near the tip of the hole 5b of the sensor case 5, a sensor element 7 is inserted which can connect and disconnect the circuit by magnetism. Lead wires 7a, 7a are connected to the sensor element 7, and the lead wires 7a, 7a are connected to the holder 8.
is held in That is, as shown in FIGS. 3 and 4, the holder 8 has a protrusion 8d having groove-shaped lead wire holding portions 8a, 8a opening outward in the radial direction and holding grooves 8b, 8b in the radial direction. The lead wire holding portion 8a and the holding groove 8e are shifted from each other in the lead wire holding position. 2
The book lead wires 7a, 7a are held separately by the holding parts 8a, 8a, and then bent into the holding groove 8.
b, 8b, and is securely held in a state where it will not shift even if it is strongly pulled. Lead wire 7
a and 7a support the sensor element with their rigidity and extend below the holder, and are connected to the socket 7c.
It is connected to the. Note that the protruding portion 8d is internally housed in the medium diameter cylindrical portion 5e, and the base plate portion 8e is
It is installed inside the large diameter cylindrical portion 5f. Further, the holder 8 has engaging claws 8c, 8c on both sides of the base plate 8e.
The claws 8c, 8c are connected to the hole 5b of the case 5.
The holder is fixed and held in the case 5 together with the sensor element 7 by engaging with engagement recesses 5r, 5r formed in the large diameter cylindrical portion 5f near the exit of the holder. On the other hand, a small diameter cylindrical part 5c whose diameter is formed to be one step narrower in the upper part of the figure from the center part of the sensor case 5.
As shown in FIG. 2, an annular float 9 is fitted into the small diameter cylindrical portion 5c so as to be slidable in the axial direction, that is, in the vertical direction in the figure. The float 9 has a built-in annular magnet 9a, and the float 9 moves up and down with the water surface along the small diameter portion 5c according to the water level in the tank 1, and the circuit in the sensor element 7 is activated by the magnetic force of the magnet. The cooling water level can be detected and alarmed intermittently.
Note that the stepped portion between the small diameter cylindrical portion 5c and the medium diameter cylindrical portion 5e serves as a stopper for the float 9. Further, a projection 5d is formed at the tip of the small diameter cylindrical portion 5c, and a hollow cylindrical damper 10 is fitted and fixed to the projection 5d in a hole 10a, as shown in FIG. The damper 10 is provided surrounding the float 9, and the upper surface of the damper 10 is provided with small holes 10b, 10b, and the lower surface is provided with the tank 1.
It is open to the inside. Therefore, even if the cooling water in the tank 1 becomes wavy due to car vibrations and the water level fluctuates significantly, the fluctuation in the water level in the damper 10 is attenuated, and the float 9 does not move blindly. In addition, the inner diameter d of the hole 1a of the tank 1
is formed to be slightly larger than the outer diameter D of the damper 10, and the damper 10 can be inserted into the tank 1 while being fixed to the sensor case 5.

Since the present invention has the above configuration, when there is a sufficient amount of cooling water in the reserve tank 1, the float 9 in the alarm device 4 floats to the upper end of the small diameter cylindrical portion 5c of the sensor case 5. The sensor element 7 and the magnet 9a inside the float 9 are kept in the same state as they are, with the sensor element 7 and the magnet 9a facing each other with the case 5 interposed therebetween. Therefore, the circuit of the sensor element 7 is kept open (or closed) by the magnetic force of the magnet 9a, and no alarm is issued. Next, when the amount of cooling water in the reserve tank 1 decreases and the water level of the cooling water in the tank 1 falls, the float 9 also moves down along the small diameter cylindrical portion 5c. When the float 9 descends, the magnetic force of the magnet 9a that has been acting on the element 7 weakens as the float 9 descends and moves away from the element 7, and when the float 9 descends beyond a certain height, the magnetic force of the magnet 9a that has been acting on the element 7 weakens. The circuit becomes closed (or open) and an alarm is issued.

By the way, when assembling such an alarm device 4, in advance, the protrusion 5d of the sensor case 5 is aligned with the third
As shown by the chain line in the figure, it is formed into a rod shape with a uniform shaft diameter, and then the float 9 is slidably fitted into the small diameter cylindrical portion 5c of the sensor case 5.
The damper 10 is fixed to the case 5 by inserting the protrusion 5d into the hole 10a of the damper 10 and deforming the tip of the protrusion 5d by heating or the like as shown by the solid line in FIG. In this state, the case 5 and the damper 10 are inserted into the reserve tank 1 through the hole 1a, and the flange 5a of the case 5 is bonded and fixed to the bottom of the tank 1. Thereafter, the sensor element 7 is inserted into the hole 5b of the case 5 with the lead wire 7a supported by the holder 8 by the holding part 8a and the holding groove 8b, and the engaging claw 8c of the holder 8 is inserted into the engaging groove of the case 5. The holder 8 is fixed to the case 5 by engaging with the holder 5r. As a result, the alarm device 4
The assembly is completed.

As explained above, according to the present invention, the process of attaching the alarm device 4 to the reserve tank 1 is extremely easy because the damper 10 etc. can be attached to the tank 1 as one piece with the damper 10 etc. fixed to the sensor case 5 in advance. It becomes possible to perform work efficiently, which can contribute to lowering product costs. Furthermore, by gluing and fixing the alarm device 4 to the bottom of the tank 1, it is possible to completely seal the inside and outside of the tank 1, so there will be no leakage of cooling water, unlike with conventional screw-in alarm devices. , it becomes possible to improve the reliability of the alarm device 4. Further, the sensor element 7 is connected to the holder 8 via the lead wire 7a.
The holder 8 is inserted into the hole 5b of the case 5 while being firmly supported by the holder 8, and the holder 8 can be securely and easily fixed to the case 5 by engaging the engaging claw 8c, thereby facilitating assembly. Since the lead wire is bent and held by the lead wire clamping portion 8a and the holding groove 8b, it is securely held by the holder and there is no chance of the sensor element being moved even if it is pulled. Furthermore, since the holder 8 with the sensor 7 mounted thereon is detachably attached to the sensor case 5 by utilizing the elastic deformation of the engaging claw 8c, it is easy to replace only the sensor element 7, and maintenance is also easy. can be done.

The sensor element 7 is normally connected by soldering both ends to the lead wire 7a, but when replacing the sensor element, remove the element 7 from the lead wire 7a taken out from the sensor case 5 and insert the new element. When connecting, it is easy to attach the element 7 at a constant distance from the substrate portion 8e, thereby making it possible to always keep the alarm water level constant. Therefore, since the water level at which the water level warning device issues an important warning can be kept constant, the reliability of the device is improved.
Reliability can be increased.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a reserve tank to which the present invention is applied, Fig. 2 is a partial sectional view taken along the - line in Fig. 1, Fig. 3 is an enlarged sectional view of the main parts, and Fig. 4 is a partial sectional view taken along the - line in Fig. 1.
The figure is a plan view showing the holder, and FIG. 5 is an enlarged sectional view of the damper mounting portion. 1: Reserve tank, 1a: Hole, 2: Cooling water,
3: Cap, 4: Water level alarm device, 5: Sensor case, 5a: Flange, 5b: Hole, 5c: Small diameter cylindrical part, 5d: Protrusion, 5e: Medium diameter cylindrical part, 5f:
Large diameter cylindrical part, 5r: engaging recess, 7: sensor element, 7a: lead wire, 7c: socket, 8: holder, 8a: lead wire holding part, 8b: holding groove, 8
c: engaging claw, 9: float, 9a: magnet,
10: damper, 10a: hole, 10b: small hole.

Claims (1)

[Scope of utility model registration request] A large-diameter cylindrical portion 5f is provided at the bottom, and a small-diameter cylindrical portion 5 is provided at the top.
The sensor case 5 has a hole 5b whose upper part is closed and the lower part is open, and an engagement recess 5r is formed on the inner surface of the lower part of the hole 5b, and the small cylindrical part 5c is inserted into the tank 1 from below. The large diameter cylindrical part 5f is fitted into the hole 1a of the tank 1 and fixed to the bottom of the tank 1 without leakage, and the small diameter cylindrical part 5
An annular float 9 having a magnet 9a is fitted on the outer surface of c so that it can be raised and lowered, and has a base plate part 8e in which an engaging claw 8c elastically protrudes laterally and a retaining groove 8b is formed. The sensor element 7 is supported by a holder 8, which has a protrusion 8d formed on the upper surface of the substrate part 8e, which has a groove-shaped lead wire clamping part 8a opening outward in the radial direction, which clamps the lead wire 7a in a bent state together with the protrusion 8d. is inserted into the lifting range of the float 9 in the hole 5b, the engaging claw 8c is elastically engaged with the engaging recess 5r, and the sensor element 7 is detachably attached to the sensor case 5 together with the holder 8. A cylindrical damper 1 with a small hole 10b formed in the closed top surface and an open bottom surface at the upper end of the damper 5.
Cooling water level alarm device for automobiles with fixed 0.