JPH0425783Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a pressure-sensitive switch used in a seating detection mechanism in riding working machines such as riding lawn mowers and tractors.

PRIOR TECHNOLOGY In general, riding work machines such as riding lawn mowers and tractors detect whether or not a worker is sitting in the driver's seat, and perform various controls such as controlling the engine when the driver leaves the seat during driving work. A seat is equipped with a seating detection mechanism to automatically stop the vehicle.

The switch used in this seating detection mechanism is disposed inside or below the seat, and is activated by pressure when the operator is seated.

The switch must be able to reliably detect whether or not the seat is occupied over a wide area of the seat, and it must be such that excessive pressing force is not applied to the switch contacts.

Therefore, in view of the above circumstances, the applicant of this application previously proposed an example of a device (Utility Model Application Publication No. 60-134031) in which the structure was specially devised.
No.) is proposed.

Problems to be Solved by the Invention In addition to the detection switch, this example requires a detection plate that is supported upward by a spring at the bottom of the seat and operates as the seat deforms, and a mounting pin that regulates the upper limit position of the detection plate. , the structure was complicated.

The present invention was devised in view of these points, and its purpose is to provide a pressure-sensitive switch that has an extremely simple structure and can detect pressing force over a wide area of the seat to reliably detect whether or not a seat is occupied. The point is that it provides

Means and Effects for Solving the Problems The present invention consists of an insulating plate that can be elastically deformed, a bracket that is disposed above the insulating plate and facing the insulating plate, has a substantially central portion fixed, and protrudes in the centrifugal direction. This pressure-sensitive switch includes an electrode provided near the side edge of a bracket, a movable electrode provided on the insulating plate facing the electrode, and a cushion member disposed below the insulating plate.

Therefore, when the pressure-sensitive switch is inserted into the seat and the worker sits on the seat, the pressure-sensitive switch is pressed from above, deforming the lower cushion member and deforming the elastic insulating plate to move the switch. Switching can be performed by bringing the electrode into contact with the electrode on the bracket side.

The structure is extremely simple, and if the insulating plate and bracket are appropriately sized, the insulating plate will deform through the cushion even if uneven pressing force is applied over a wide area of the seat, making it easy for the operator to use. seating can be reliably detected.

Embodiment An embodiment of the present invention illustrated in FIGS. 1 to 5 will be described below.

This embodiment is an example in which it is applied to a seat of a riding lawnmower, and FIG. 2 is a cross-sectional view showing a state in which the pressure-sensitive switch 2 according to this embodiment is inserted inside the seat 1 at approximately the center of the seating area. It is a diagram.

The pressure sensitive switch 2 has a disk shape, and a lead wire 3 extends from the bottom thereof.

The pressure sensitive switch 2 is inserted into the cushion material 4 of the seat 1 at the position shown in FIG. 2 to detect whether a worker is seated.

FIG. 1 shows a longitudinal sectional view of the pressure sensitive switch 2, and FIG. 3 shows an exploded perspective view thereof.

Reference numeral 5 denotes a disk-shaped insulating plate made of resin, for example, made of acrylic resin and having a circular hole in the center.

The insulating plate 5 is easily elastically deformed.

A terminal ring 6 made of a conductor is placed over the outer periphery of the insulating plate 5.

The terminal ring 6 has a U-shaped cross section and has a portion 6a that fits the outer peripheral edge of the insulating plate 5, and a portion 6a that protrudes diagonally upward and inward from the upper inner edge of the U-shaped portion 6a. The electrode terminal portion 6b functions as an electrode and also serves to strengthen the rigidity of the insulating plate 5.

A bracket 7 is disposed on the upper side of the insulating plate 5 so as to face it, and its central recess is fixed to the insulating plate 5 with a rivet 8.

The rivet 8 passes through the central circular hole of the bracket 7 and the circular hole of the insulating plate 5, and the bracket 7 is fixed to the insulating plate 5 through a washer 9 at the lower part of the insulating plate 5.

The bracket 7 is press-formed from a steel plate and has a circular shape with a recess in the center, and its outer peripheral end is bent vertically downward and then further bent in the centrifugal direction to form a stopper 7a.

When no external force is applied, the insulating plate 5, terminal ring 6, bracket 7, and their respective parts are in the positional relationship shown in FIG.

The terminal ring 6 and the bracket 7 are insulated by the insulating plate 5, and the upper electrode terminal portion 6b of the terminal ring 6
There is an empty space between the bracket 7 and the bracket 7.

The switch unit formed in this manner is covered with a cushion material 10 made of foamed urethane from above and below, and then covered with a coating 11 such as polyethylene, and the outer peripheral edges of the upper and lower coatings 11 are welded together to form the switch unit. It is sealed to make it waterproof.

Note that a portion of the lower coating 11 has an opening for drawing out the lead wire 3, and this opening is pressed against the outer coating of the lead wire 3 in a watertight manner.

The lead wire 3 is a bundle of two wires, each of which is covered with vinyl.

One lead wire 3a is inserted through the opening in the coating 11, and then its end is connected to a washer 9 placed on the lower center of the insulating plate 5, and the washer 9, rivet 8, and bracket 7 are all conductors. Therefore, the lead wire 3a and the bracket 7 are in a conductive state.

The other lead wire 3b is connected to the terminal ring 6 after being inserted through the opening of the coating 11.

The pressure-sensitive switch 2 according to this embodiment is constructed as described above and has a compact disc-like shape.

Such a pressure sensitive switch 2 is inserted into the cushion of the seat 1 as shown in FIG.

When the operator is seated normally, the entire pressure sensitive switch 2 sinks evenly, and the terminal ring 6 supported by the lower cushion material 10 is elastically deformed as shown in FIG.

The center of the insulating plate 5 is sandwiched between the bracket 7 and the washer 9 and fixed with a rivet 8, and the area near the outer periphery is fitted with the U-shaped part 6a of the terminal ring 6.
The terminal ring 6 is deformed between the center and the outer periphery while maintaining appropriate rigidity, and the electrode terminal portion 6b comes into contact with the bracket 7 with the terminal ring 6 rising, and the lead wires 3a and 3b are short-circuited.

When the pressure exceeds a certain level, the stopper 7a provided on the outer peripheral edge of the bracket 7 contacts and supports the terminal ring 6, so that the electrode terminal portion 6b can be protected.

The case where the pressing force acts on the entire pressure-sensitive switch 2 has been described above, but when the pressing force acts on a portion of the pressure-sensitive switch 2, the situation is as shown in FIG.

That is, FIG. 5 shows an example in which the pressing force acts only on the left side of the pressure sensitive switch 2.

When a pressing force is applied from above on the left side of the bracket 7, the left side of the pressure sensitive switch 2 sinks, the left side of the insulating plate 5 supported by the cushion material 10 is elastically deformed, and the electrode terminal portion 6a of the terminal ring 6 is pushed into the bracket. Contact 7.

Since the pressure-sensitive switch 2 has a disk shape, it can perform the above-described switching operation in response to a localized pressing force at either the front, back, left or right of the center.

Therefore, when such a pressure-sensitive switch 2 is inserted into the interior of the cushion material 4 of the seat, the cushion material 4 will not be deformed even if the pressure is applied not directly above the pressure-sensitive switch 2 but in the vicinity. By applying pressure to the pressure switch 2, the insulating plate 5 is deformed and the terminal ring 6 and the bracket 7 can be brought into contact as shown in FIG.

That is, the pressure sensitive switch 2 has a wide operable area, and can detect whether or not a person is seated over a wide area of the seat 1.

As described above, the pressure-sensitive switch according to this embodiment has an extremely simple structure and high reliability, and is compact in shape with a thin disc shape, so it is easy to embed in the seat, reducing costs. be able to.

Even though it is compact, it is possible to detect whether or not a person is seated over a wide area of the seat.

The entire switch unit is covered with a sealing film to prevent problems caused by water intrusion.

Next, another modification is shown in FIG. 6 and will be described.

Reference numeral 20 denotes a disc-shaped insulating plate made of acrylic resin, which has a circular hole in the center and is easily elastically deformed.

An annular copper plate 21 is attached concentrically to the upper surface of the insulating plate 20, and a terminal 22 is attached to the insulating plate 20 by penetrating the insulating plate 20 at a part of the attached part of the copper plate 21.
is exposed on the back side.

A lead wire 23 extends from the terminal 22.

On the upper side of the insulating plate 20, there is a bracket 24 opposite to the upper side of the insulating plate 20.
is arranged, and the central recess is fixed to the insulating plate 20 with a bolt 25 via a washer 26.

The bracket 24 is press-formed from a steel plate and has a shape similar to that of the bracket in the previous embodiment, with a stopper 24a formed on the outer periphery.

Then, on the lower surface of the bracket 24, an annular electrode terminal 27 is attached at its inner periphery to the bracket 24, and parallel to the horizontal plane at a slightly lowered position near the outer periphery (copper plate 21 attached to the insulating plate 20).
(opposed to).

electrode terminal 27, bracket 24, bolt 25,
The washers 26 are all conductors and are in a conductive state, and the washers 26
A lead wire 28 is connected to.

The above switch unit is covered with a foamed urethane cushion material 29 and a polyethylene coating 30, as in the previous embodiment.

When the worker sits on the seat, a pressing force is applied from above, causing the insulating plate 20 to elastically deform as in the previous embodiment, causing the copper plate 21 to come into contact with the electrode terminal 27, and the lead wire 2
3 and 28 are shorted.

It can also operate in response to local pressing force, and the effect is the same as in the previous embodiment.

In addition to the above-mentioned embodiments, various structures of the contact portion can be considered, but any structure that allows contact by deformation of the elastic insulating plate can be applied.

Effects of the invention Since the structure of the invention is extremely simple, it can be provided at low cost and is highly reliable.

Also, since it is thin and compact, it is easy to attach to the seat.

Furthermore, due to its structure, it is possible to reliably detect whether or not a person is seated over a wide area of the seat.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of one embodiment of the present invention;
The figure is a sectional view showing the pressure-sensitive switch of this embodiment inserted into the seat, Figure 3 is an exploded perspective view of the switch unit of this embodiment, and Figures 4 and 5 are when a pressing force is applied. FIG. 6 is a cross-sectional view of a pressure-sensitive switch according to another embodiment. DESCRIPTION OF SYMBOLS 1...Seat, 2...Pressure sensitive switch, 3...Lead wire, 4...Cushion material, 5...Insulating plate, 6...
...Terminal ring, 7...Bracket, 8...Rivet, 9...Washer, 10...Cushion material, 11...
...Coating, 20... Insulating plate, 21... Copper plate, 22...
... terminal, 23 ... lead wire, 24 ... bracket, 25 ... bolt, 26 ... washer, 27 ... electrode terminal, 28 ... lead wire, 29 ... cushion material, 30 ... polyethylene coating.

Claims (1)

[Scope of utility model registration request] An insulating plate that can be elastically deformed, a bracket that is placed opposite the insulating plate on the upper side and has a substantially central portion fixed and protrudes in the centrifugal direction, an electrode provided near the side edge of the bracket, and an electrode that 1. A pressure-sensitive switch comprising: a movable electrode provided on the insulating plate to face the insulating plate; and a cushion member disposed below the insulating plate.