JPS6347728Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cigarette lighter that can cope with the situation where the heat generating part of the lighter plug becomes overheated within the socket.

Conventionally, for example, in a cigarette lighter for an automobile, a male terminal made of a fusible metal is attached to the tip of a bimetal finger terminal that protrudes rearward from the back wall of the socket, and this male terminal is connected to a power line. It is common that the female terminals are connected together, and for example, if the lighter plug is held in the pushed-in state for a long time due to misuse, or if the electric heater, which is the heat generating part at the tip of the lighter plug, is fired. When the electric heater becomes overheated, the male terminal is blown out. However, in the above conventional configuration,
Male terminals made of fusible metal have poor thermal response, and
Because it takes time for the heat of the electric heater to be transferred to the male terminal via the bimetal finger and the terminal for the bimetal finger, there is a problem that the male terminal cannot be quickly fused when the electric heater becomes overheated. There was also the problem that when the male terminal fused, the entire unit had to be replaced even if there was no abnormality in the other parts.

The present invention was developed in view of the above circumstances.The purpose of this invention is to be able to quickly stop the current flowing to the heat generating part when it becomes overheated, and to minimize the need for replacing the entire heat generating part. To provide a cigarette lighter that can be removed.

To summarize the present invention, the present invention is characterized by a configuration in which a positive temperature coefficient thermistor, which is interposed in the current conduction path of the heat generating part of the lighter plug, is disposed deep inside the socket. The purpose is to prevent the current from flowing to the heat-generating part by increasing the value to an extremely large value.

An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes, for example, an instrument panel which is a part to be attached to an automobile, and a mounting opening 2 is formed in this instrument panel. Reference numeral 3 denotes a socket, which has a cylindrical shape with one end (left end) closed, and a flange portion 4 projecting outward is formed at the other open end, and an axially extending flange portion 4 is formed in the middle portion. A plurality of slit-shaped insertion holes 5 and a plurality of holding pawls 6 are formed. Reference numeral 7 designates a bimetal finger terminal, which has a flange 7a formed at its base end and a threaded portion 7b formed at its distal end. 8 is a disc-shaped insulator, and a shaft cylinder part 8a is provided in the center of the insulator.
is formed, and this shaft cylindrical portion 8a is fitted into the base end portion of the bimetal finger terminal 7. Reference numeral 9 denotes a disk-shaped electrode body having a contact piece portion 9a, which is fitted into the shaft cylinder portion 8a of the insulator 8. Reference numeral 10 denotes a disk-shaped positive temperature coefficient thermistor, which is fitted into the cylindrical portion 8a of the insulator 8 so that one surface thereof is in contact with the electrode body 9. Reference numeral 11 denotes a disk-shaped electrode body, which is fitted into the base end of the bimetal finger terminal 7 and connected to the positive temperature coefficient thermistor 1.
0 and comes into contact with the other surface. The insulator 8, electrode body 9, positive temperature coefficient thermistor 10, and electrode body 11 are fixed to the base end of the bimetal finger terminal 7 by caulking a portion of the base end. Thus, the bimetal finger terminal 7 is connected to the insulating washer 1.
2 and a base 13 made of an insulating material, which is in the shape of a short cylinder with a bottom, and is inserted into a seat 14 made of an insulating material. The threaded portion 7b projects rearward from the back wall of the socket 3, and an insulating washer 15 and a washer 1 are attached to the threaded portion 7b.
The nut 17 is screwed together through the seat 1.
4 is fixed to the back wall of socket 3. In this case, the contact piece portion 9a of the electrode body 9 is adapted to come into contact with the inner surface of the peripheral wall of the base 13. Reference numeral 18 denotes a metal thermistor case in the shape of a stepped short cylinder with one end closed;
It is fitted and fixed to the peripheral wall of the seat 14 and the front end of the seat 14. A bimetal finger 19 is attached to a rivet 19a at the closed end of the thermistor case 18.
It is installed and fixed by. The socket 3 is attached to the instrument panel 1 by being inserted into the mounting opening 2 of the instrument panel 1 and being engaged with the periphery of the mounting opening 2. Reference numeral 20 denotes an assembly guard that is inserted into the socket 3 so as to be movable in the axial direction, that is, the left and right direction, and has a substantially cylindrical shape, and has a flange portion projecting outward at one (right) open end thereof. 20a is formed, and a locking groove portion 20b that protrudes inward is formed in the intermediate portion, the flange portion 20a is locked to the flange portion 4 of the socket 3, and the locking groove portion 20b is connected to the holding claw. 6, and thus the attachment guard 20 is removably held within the socket 3. 21 is a writer plug, which will be explained below. That is, 22 is a stepped cylindrical slide ring having a locking step 22a in the middle, and a flange 22b projecting outward is formed at the open end on the larger diameter side. And this slide ring 2
The large diameter portion of No. 2 is fitted into the attachment guard 20 so as to be movable in the left and right direction, and the flange portion 22b thereof
is locked to the flange portion 20a. 23
is a cylindrical plug body with one end (left end) closed, and a stepped short cylindrical cap 24 having a locking step 24a in the middle is fixed to the other open end by caulking or the like. has been done. Further, a heater case 27 having a locking step 27a is attached to the closed end of the plug body 23 via an insulator 25 and an insulating washer 26 with a rivet 28. An electric heater 29 serving as a heat generating portion is attached to the holder, and a central portion of the electric heater 29 is connected to one end portion 28a of the rivet 28. The outer periphery of the closed end of the plug body 23 is fitted into the small diameter portion of the slide ring 22 so as to be movable in the left and right direction, and the outer periphery of the large diameter portion of the cap 24 is fitted into the large diameter portion of the slide ring 22 in the left and right direction. The slide ring 2 is movably fitted to the slide ring 2.
The locking step 22a of the cap 2 and the locking step 2 of the cap 24
4a is a return compression coil spring 30.
is interposed, and this compression coil spring 3
The spring force of 0 normally biases the slide ring 22 in the leftward direction of arrow 31, and also biases the plug body 23 and hence the heater case 27 in the opposite direction to the rightward direction of arrow 31. Then, the flange portion 22b of the slide ring 22 is locked to the flange portion 20a of the assembly guard 20, and the movement of the slide ring 22 in the direction of arrow 31 is restricted, and the locking step portion 27a of the heater case 27 is locked to the slide ring 20a. The heater case 27 and the plug body 23 are stopped from moving in the direction opposite to the direction of the arrow 31 by being locked to the open end of the heater case 22 on the small diameter side. It is designed to be held at the original position shown in Figure 1. Note that 32 is a knob attached to the cap 24. As for the electrical configuration, the bimetal finger terminal 7 is connected to the positive terminal of a battery (not shown), and the socket 3 is connected to the positive terminal of a battery (not shown).
is connected to the negative terminal (ground) of the battery.

Next, the operation of this embodiment will be explained. When the user presses the knob 32 with his or her finger in the state shown in FIG.
When is pressed, the plug body 23 and the heater case 27 are pushed and moved in the direction of the arrow 31, and the heater case 27 is fitted and locked to the bimetal finger 19, and the lighter plug 21 except the slide ring 22 is in the operating position. (See Figure 2). When the lighter plug 21 is locked in the operating position, the positive terminal of the battery, the bimetal finger terminal 7, the electrode body 11, the positive temperature coefficient thermistor 10, the electrode body 9, the contact piece portion 9a, the base 1
3. Thermistor case 18, bimetal finger 19, heater case 27, electric heater 29, rivet 28, plug body 23, slide ring 2
2. The path of the assembly guard 20, the socket 3, and the negative terminal of the battery forms an energizing path for the electric heater 29. Therefore, the positive temperature coefficient thermistor 10 is connected in series with the bimetal finger 19, and the electric heater 29 This means that it is interposed in the current-carrying path. In this case, since the electrical resistance value of the PTC thermistor 10 is small at the beginning of the current supply to the PTC thermistor 10, a sufficiently large current flows through the electric heater 29, and the electric heater 29 starts generating heat. . After that, when the electric heater 29 reaches the set temperature, the bimetal finger 19 senses this and expands, so the bimetal finger 19 releases the heater case 27 and the lighter plug 21 is compressed. Due to the spring force of the coil spring 30, it is returned from the operating position in the direction opposite to the direction of the arrow 31, which is the direction of the original position. Therefore, when the user picks up the knob 32 and pulls it in the opposite direction to the direction of the arrow 31, the attachment guard 20
The lighter plug 21 is pulled out from the socket 3 in an integrated state.

By the way, for example, if the lighter plug 2
When the electric heater 29 becomes overheated due to the electric heater 29 being held in the pressed state for a long time and current continues to flow through the electric heater 29, or when the electric heater 29 is shorted, the positive temperature coefficient thermistor 10 The electric current flowing through the device causes self-heating, and the heat from the electric heater 29 heats the bimetal finger 19 and the thermistor case 18, so the electric resistance value of the positive temperature coefficient thermistor 10 becomes extremely large, causing a current to flow through the electric heater 29. Therefore, the electric heater 29 is substantially cut off from current flow.

According to this embodiment, the following effects can be obtained. That is, the positive temperature coefficient thermistor 10 is disposed on the seat 14 close to the bimetal finger 19, and the positive coefficient thermistor 10 is interposed in the current conduction path of the electric heater 29 via the bimetal finger 19. When the PTC thermistor 29 becomes overheated, the PTC thermistor 10 exhibits an extremely large electrical resistance value due to the heat, thereby blocking the current flowing to the electric heater 29. This also has the advantage that current to the electric heater 29 can be quickly blocked. In addition, the positive temperature coefficient thermistor 10 does not melt when it is overheated, but simply increases its electrical resistance, and returns to its original state when it cools down naturally.
In the case of misuse where the lighter plug 21 is pushed in and held for a long time, it can be reused if the lighter plug 21 is released, and if the electric heater 29 of the lighter plug 21 is fired, the lighter All that is needed is to replace the plug 21, and therefore, there is no need to replace the entire device unless the bimetal finger 19 on the socket 3 side breaks down. Furthermore, since the positive temperature coefficient thermistor 10 generates heat by itself according to the flowing current and changes its electrical resistance value to increase, the bimetal finger 19 senses the set temperature and locks the heater case 27 of the lighter plug 21. By the time the positive temperature coefficient thermistor 10 is released, it exhibits a relatively large electrical resistance value and comes to suppress the current flowing to the electric heater 29. Therefore, when the heater case 27 separates from the bimetal finger 19, It is possible to prevent arcs from occurring between these as much as possible, and therefore the bimetal fingers 19 have poor arc resistance.
The lifespan of can be extended.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can of course be implemented with appropriate modifications within the scope of the invention.

As explained above, the present invention has a configuration in which a positive temperature coefficient thermistor is disposed deep inside the socket, and this positive coefficient thermistor is interposed in the current conduction path via the bimetal finger of the heat generating part at the tip of the lighter plug. Therefore, it is possible to provide a cigarette lighter that can promptly stop the current flowing to the heat generating part when the heat generating part becomes overheated, and has the practical effect of eliminating the need for replacing the entire part as much as possible. It is something.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional view, FIG. 2 is an enlarged longitudinal sectional view of the main part, and FIG. 3 is a longitudinal sectional view of the device in its operating state. In the drawing, 3 is a socket, 7 is a terminal for bimetal fingers, 10 is a positive temperature coefficient thermistor, 14
19 is a bimetal finger, 21 is a lighter plug, 27 is a heater case (tip part), 29 is an electric heater (heating part), and 30 is a compression coil spring.

Claims (1)

[Scope of utility model registration request] A lighter plug is provided so as to be pushed into the socket and has a heat generating part at its tip and is always biased toward the original position; a bimetal finger that locks its tip when the heat generating part is turned on and releases the lock when the heat generating part is energized and a set temperature is sensed; A cigarette lighter comprising a positive characteristic thermistor.