JPH04124428U - Vehicle liquid level detection device - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to reduce costs, make the product smaller and lighter, and reduce indication errors. [Structure] A holder 15, which is a holding means for holding the sensing part 3, is slidably fitted to the outer periphery of the outer electrode 2b of the coaxial cylindrical electrode 2, and the sensing part 3 is attached to the holder 15.
is provided so that it can slide. The sensing part 3
Since it is urged downward by the coil spring 6, it is always pressed against the bottom surface 5 of the fuel tank.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a vehicle liquid level detection device for detecting a fuel liquid level in a fuel tank.

0002

[Conventional technology]

Conventionally, variations in fuel tank dimensions and expansion or contraction of the fuel tank have been Since the fuel level fluctuates with There is a bottom-based liquid level detection device that can detect the remaining liquid level more accurately. Ru.

0003 For example, as shown in FIG. A guide rod 101 is provided, and the guide rod 101 is slidably held by a holder 102. By doing so, the sensing unit 100 can be slid vertically, and the sensor As the sing part 100 is urged downward by the spring 103, the sensing part 100 The plug portion 100 can always be kept pressed against the bottom surface 104 of the fuel tank. Wear.

0004 Furthermore, in the liquid level detection device disclosed in Japanese Utility Model Application Publication No. 60-148930, the fuel Float arm type sensor using the discharge pipe and return pipe as a guide A structure that slides up and down has been proposed.

[0005]

[Problem that the idea aims to solve]

However, in all of the above liquid level detection devices, in addition to the sensing section, there is also a sensing section. A guide part is required to slide the holding part in the vertical direction. this This has become an obstacle to reducing costs and making products smaller and lighter. There is.

[0006] Furthermore, as shown in Figure 8, the conventional liquid level detection device receives the signal from the sensing section. The lead wire 105 to be transmitted is held by the lead wire holding section 106, The lead wire 105 is not held in a hollow state, and the lead wire is held over a certain length. This structure supports the lead wire 105. Therefore, as shown in FIG. Due to fuel adhering to the ground lead wire 107, the stray capacitance between the Also, the electric lines of force act through the lead wire holding part 106, which causes a large indication error. arise.

[0007] This invention was developed based on the above circumstances, and its purpose is to reduce the number of parts. By doing so, we can reduce costs, make products smaller and lighter, and An object of the present invention is to provide a liquid level detection device for a vehicle that reduces indication errors.

[0008]

[Means to solve the problem]

In order to achieve the above object, the present invention provides that, in claim 1, A sensing part consisting of a coaxial cylindrical electrode arranged and a sensing part made of a coaxial cylindrical electrode that slides on the outer periphery of the coaxial cylindrical electrode. It has a holder that is freely fitted together, and the holder and the sensing section are connected to each other. The sensing portion is maintained so that it can relatively slide vertically within the fuel tank. and a biasing hand that presses the sensing portion toward the bottom surface of the fuel tank. a stage, the static sensing unit detects changes in the liquid level height from the bottom of the fuel tank. The technical means is to detect it as a change in capacitance.

[0009] Further, in claim 2, the lead wire for transmitting the signal from the sensing section is hollow. The technical means is that a lead wire holder is provided to hold the lead wire in this state.

0010

[Effects of action and invention]

The liquid level detection device for a vehicle according to claim 1 is slidably fitted to the outer periphery of a coaxial cylindrical electrode. The combined holder and sensing part slide relative to each other in the vertical direction inside the fuel tank. By pressing the sensing part against the bottom of the fuel tank, , the sensing part can always be kept in contact with the bottom of the fuel tank.

[0011] Therefore, the liquid level height from the bottom of the fuel tank can be accurately detected. Also, the sensing unit itself provides a guide when sliding vertically relative to the holder. By functioning as a guide, there is no need for guide parts other than the sensing part. The number of parts can be reduced compared to conventional liquid level detection devices. As a result, cost reduction This makes it possible to reduce the size and weight of the product.

0012 Further, in the vehicle liquid level detection device according to claim 2, the lead wire is held in a hollow state. By doing so, less fuel adheres to the outer circumference of the lead wire, and the ground lead wire Since the change in stray capacitance during this period is reduced, the indication error can be reduced.

[0013]

【Example】

Next, a liquid level detection device for a vehicle according to the present invention will be explained based on an embodiment shown in the drawings. FIG. 1 is an overall view of a vehicle liquid level detection device, FIG. 2 is a view from A in FIG. 1, and FIG. 3 is a view from B in FIG. It is a sectional view of B.

[0014] This liquid level detection device 1 includes a sensing section 3 consisting of three sets of coaxial cylindrical electrodes 2; An oscillation circuit 4 that converts the change in capacitance of the sensing unit 3 into a frequency, and a fuel tank A holding means (described later) that holds the sensing unit 3 in the storage compartment (not shown) and a sensor A coil spring 6 (the biasing force of the present invention) that presses the singe portion 3 against the bottom surface 5 of the fuel tank. It consists of means)), etc.

[0015] The coaxial cylindrical electrode 2 is shown in FIGS. 2 and 4 (enlarged sectional view of the coaxial cylindrical electrode 2). In this way, the inner electrode 2a and the outer electrode 2b forming a cylinder are arranged coaxially, and both ends thereof are completely disposed. It is held by edge caps 7 and 8. 3 sets of coaxial cylinder electric The poles 2 are arranged in a triangular shape (see Figure 3), with each inner electrode having a positive potential. The pole 2a is connected to each terminal 9 assembled on the cap 7, and each outside of the negative potential The electrode 2b is commonly connected to the ground lead wire 10. Each terminal 9 has a The lead wire 11 is connected to the oscillation circuit 4 together with the ground lead wire 10. has been done.

[0016] As shown in FIG. 4, this coaxial cylindrical electrode 2 The inside of the fuel tank is inserted into the space between the inner electrode 2a and the outer electrode 2b through the inlet 8a. of fuel flows in, and the capacitance between electrodes 2a and 2b changes depending on the displacement of the liquid level. do.

[0017] The holding means includes a flange 12 for attachment to the fuel tank, and is integrated with this flange 12. a bracket 13, an arm 14 supported by this bracket 13, and It consists of a holder 15 attached to the tip of an arm 14.

[0018] The flange 12 is attached to the fuel tank in order to insert the liquid level detection device 1 into the fuel tank. is fixed to the outer peripheral wall surface of the opening 16 formed in the side wall of the fuel tank. An oscillation circuit 4 is attached to the outside). The flange 12 also has an oscillation circuit. In order to establish continuity between the line 4 and the lead wire 11 and ground lead wire 10 from each terminal 9. A plurality of terminals 17 are inserted.

[0019] The bracket 13 is made of resin and is integrally formed with the flange 12, and each lead wire 11 Lead wire holding parts 18 and 19 for holding the ground lead wire 10 are provided. It is. The lead wire holding section 18 that holds each lead wire 11 is shown in FIG. As shown in the perspective view of There are three locations. Each lead wire holding portion 18 supports the lead wire 11. In order to reduce the amount of fuel that adheres between the recess (not shown) and the lead wire 11, In order to It is configured to hold the lead wire 11 in a hollow state.

[0020] Further, the lead wire holding portion 19 that holds the ground lead wire 10 is connected to the bracket 13. It is provided over a predetermined length on the lower surface side of the. This lead wire holding part 19 - Since the recess that supports the three lead wire 10 is opened downward, there is a connection between the recess and the ground. Almost no fuel adheres between the lead wire 10 and the lead wire 10. Therefore, the lead wire holding section 18, a structure for holding the lead wire 11 in a hollow state is not adopted.

[0021] The arm 14 extends downward from the bracket 13 and has a resin holder at its lower end. 15 is attached. As shown in FIG. 3, the holder 15 is slidable on the outer periphery of the two outer electrodes 2b. It is fitted in.

[0022] The above-mentioned sensing part 3 is a coil spring secured to the tip of the bracket 13. It is urged downward by the ring 6 (biasing means of the present invention) and pushed against the bottom surface 5 of the fuel tank. I'm under pressure.

[0023] The liquid level detection device 1 of this embodiment having such a configuration detects expansion and contraction of the fuel tank. Accordingly, the positional relationship between the bottom surface 5 of the fuel tank and the attachment part of the flange 12 When the dimensional relationship in the vertical direction) changes, the holder 15 and the outer electrode 2b are relatively Slide to . Therefore, the sensing part 3 which is urged downward by the coil spring 6 , its lower end can always remain in contact with the bottom surface 5 of the fuel tank. As a result, even if the dimensions of the fuel tank change as described above, the liquid from the tank bottom 5 Surface height can be detected accurately.

[0024] When the sensing part 3 slides, the outer electrode 2b itself acts as a guide. This eliminates the need for a guide component separate from the sensing section 3 as in the past. Therefore, the number of parts can be reduced. As a result, it becomes possible to reduce costs In both cases, the product can be made smaller and lighter.

[0025] In addition, since the structure holds each lead wire 11 in a hollow state, the lead wire 11 The amount of fuel adhering between 1 and the recess is reduced. As a result, the ground lead wire 10 and The change in stray capacitance during this period is reduced, and the indication error can be reduced.

[0026] Although this embodiment shows an example in which the holder 15 is provided in one place, there are multiple holders in the vertical direction. As shown in FIG. It is also possible to provide a door portion 7a to further stabilize the sliding portion. Further, although three sets of coaxial cylindrical electrodes 2 are used, the number is not limited to three sets.

[Brief explanation of drawings]

FIG. 1 is an overall view of a vehicle liquid level detection device.

FIG. 2 is a view from A in FIG. 1;

FIG. 3 is a sectional view taken along line BB in FIG. 1;

FIG. 4 is an enlarged cross-sectional view of a coaxial cylindrical electrode.

FIG. 5 is a perspective view of a lead wire holding section.

FIG. 6 is a plan view of a sensing section showing a modification of the present embodiment.

FIG. 7 is an overall view of a vehicle liquid level detection device according to the prior art.

FIG. 8 is a perspective view of a lead wire holding section showing a conventional technique.

FIG. 9 is a cross-sectional view of a lead wire holding section showing a conventional technique.

[Explanation of symbols]

1 Vehicle liquid level detection device 2 Coaxial cylindrical electrode 3 Sensing part 6 Coil spring (biasing means) 11 Lead wire 12 Flange (holding means) 13 Bracket (holding means) 14 Arm (holding means) 15 Holder (holding means) 18 Lead wire holding part

Claims (2)

[Scope of utility model registration request] Claims: 1. A sensing unit comprising a) a coaxial cylindrical electrode arranged in a fuel tank of a vehicle, and b) a holder slidably fitted to the outer periphery of the coaxial cylindrical electrode, the holder and the sensing part comprising a coaxial cylindrical electrode. c) a holding means for holding the sensing part so as to be able to relatively slide vertically within the fuel tank; and c) urging means for pressing the sensing part against a bottom surface of the fuel tank. , a liquid level detection device for a vehicle that detects a change in the height of the liquid level from the bottom surface of the fuel tank as a change in capacitance of the sensing section; 2. The liquid level detection device for a vehicle according to claim 1, further comprising a lead wire holding portion that holds the lead wire transmitting the signal from the sensing portion in a hollow state.