JPH0237253Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is applicable to, for example, a rubber hole used to protect or improve the insulation of the wire hole that communicates between the inside and outside of a motor housing, and the wires and other electrical circuits inserted through the hole. Regarding grommets.

[Conventional technology]

Conventionally, a rubber grommet is made of rubber and has a cross-sectional shape as shown in Fig. 3 a, and is fitted into a hole b provided in a housing of an electric motor, etc., and this part maintains watertightness between the rubber grommet and the hole b. It is secured. Further, an electric circuit is inserted into the inner peripheral portion so as to be in contact with this, and watertightness between the electric circuit and the electric circuit is ensured at this portion.

[The problem that the idea attempts to solve]

However, in such a device, the outer circumferential portion of the inner circumferential portion in contact with the electric circuit is restrained by the hole b. For this reason, if the electrical circuit is used for a long period of time with bends caused by connection with other equipment, the inner periphery may not be able to follow the electrical circuit and the watertightness will be broken, or the outer periphery in which it is fitted will be subject to force. As a result, there was a problem that the watertightness was broken at the outer periphery and water entered.

Furthermore, since the electrical circuit comes into contact with the entire inner circumference of the rubber grommet, there is a problem in that a large force is required to insert the electrical circuit.

This idea was made in view of the problems of conventional technology, and its purpose is to prevent electrical circuits that have been used for long periods of time with bends caused by connections to other devices. The main purpose of the present invention is to provide a rubber grommet that has the main purpose of ensuring watertightness even in cases where electrical circuits can be inserted easily.

[Means to solve the problem]

In order to achieve the above object, the rubber grommet in this invention is a cylindrical rubber grommet consisting of an outer peripheral part 1a that is press-fitted into a hole for an electric wire communicating between the inside and outside of the machine frame, and an inner peripheral part 1b into which an electric circuit is inserted. A reinforcing ring 4 made of metal is included in the cylindrical body at a portion corresponding to the wire hole of the machine frame, and a reinforcing ring 4 is formed in the axial direction of the cylindrical body and toward the outside of the machine frame with respect to the reinforcing ring 4. The present invention is characterized in that an annular seal lip 1c having an inner diameter smaller than the outer diameter of the electric circuit to be inserted is locally formed in the inner peripheral portion 1b at a predetermined distance from the inner circumferential portion 1b.

[Effect]

The effect of the above means is as follows.

Since the rubber grommet 1 includes a reinforcing ring 4 in the corresponding part when press-fitting into the wire hole of the machine frame, it generates a resistance commensurate with the press-fitting amount into the wire hole, and this generates a frictional force. A certain amount of pull-out load (resistance to pull-out) is ensured.

In addition, the annular seal lip 1c is formed on the inner circumferential portion 1b at a predetermined distance from the reinforcing ring 4 in the axial direction of the cylindrical body and outward of the machine frame, so that there is no need to connect other equipment to the electrical circuit. Even if it is used for a long period of time with bends caused by connections, it can follow the electrical circuit. Moreover, even if the seal lip 1c follows the electric wire, due to the distance and the inclusion of the reinforcing ring 4, no force is applied to the part that is press-fitted into the electric wire hole. The initial press-fitting state can be maintained without any additional pressure applied.

Furthermore, the rubber grommet 1 is in local contact with the electrical circuit through the sealing lip 1c.
Since a clearance is formed in the inner circumferential portion other than point c, the electric circuit can be inserted easily without requiring a large force.

〔Example〕

FIG. 1 is a partially cutaway side view of the electric motor, and FIG. 2 is a cross-sectional view of the main part of this invention.

1 is a rubber grommet according to this invention,
It is not much different from the conventional one in that it is made of a rubber-like elastic material. A rubber grommet 1 has an outer circumferential portion 1a that is press-fitted into a wire hole 2a that communicates the inside and outside of a machine frame 2 such as an electric motor, and an inner circumferential portion 1 into which an electric wire 3 forming an electric circuit is inserted.
It forms a cylindrical body consisting of b. Reference numeral 4 denotes a metal reinforcing ring which is inserted into a portion corresponding to the press-fitting of the wire hole during molding of the rubber grommet 1, and is formed of a steel plate into an annular shape having an L-shaped cross section. Reference numeral 1c denotes an inner peripheral portion 1 that is spaced a predetermined distance from the reinforcing ring 4 in the axial direction of the cylindrical body and outward of the machine frame.
b, and is an annular seal lip whose inner diameter is smaller than the outer diameter of the electric circuit to be inserted, and in the free state forms a ridge with a chevron-shaped cross section as shown in FIG. 2b. In the inner peripheral part other than this seal lip 1c, the electric wire 3
A clearance is formed between the two. Numeral 5 is a snap spring that presses the annular seal lip 1c inward to increase the pressing force against the surface of the electric wire 3, thereby increasing watertightness.

When this rubber grommet 1 is used, it is press-fitted into an electric wire hole 2a provided in a machine frame 2 of an electric motor, etc., and then the electric wire is inserted into the inner periphery 1b, and the snap ring 5 is hung on the outer periphery to complete the assembly.

During this assembly, there is no need to fit the wire into the wire hole in the machine frame as in the conventional example, and the wire can be simply driven or pushed in, so the assembly work is easy.

Reference numeral 6 indicates an annular recess formed when caulking is performed to prevent the rubber grommet 1 from coming off.

In addition, in the above description, the snap spring 5 and caulking are not essential requirements for the configuration of this invention.

[Effect of idea]

According to this invention, since the rubber grommet 1 includes the reinforcing ring 4 in the corresponding part when press-fitting into the wire hole of the machine frame, it generates a resistance commensurate with the press-fitting amount into the wire hole. However, this becomes a frictional force to ensure a constant pull-out load (difficulty in pulling out).

In addition, the annular seal lip 1c is formed on the inner circumferential portion 1b at a predetermined distance from the reinforcing ring 4 in the axial direction of the cylindrical body and outward of the machine frame, so that there is no need to connect other equipment to the electrical circuit. Even if the cable is used for a long period of time in a state where it is bent due to the connection, it can follow the electrical circuit and maintain watertightness. Moreover, even if the seal lip 1c follows the electric wire, due to the distance and the inclusion of the reinforcing ring 4, no force is applied to the part that is press-fitted into the electric wire hole. Since the initial press-fitted state can be maintained without any pressure applied, watertightness can be ensured even at the outer periphery.

Furthermore, the rubber grommet 1 is in local contact with the electrical circuit through the sealing lip 1c.
Since a clearance is formed in the inner circumferential portion other than point c, the electric circuit can be inserted easily without requiring a large force.

[Brief explanation of drawings]

The drawing shows an example of this invention.
FIG. 1 is a partially cutaway side view of an electric motor, FIG. 2 is a sectional view of the main part of this invention, and FIG. 3 is a sectional view of a conventional example. 1...Rubber grommet, 1a...Outer periphery, 1
b...Inner peripheral part, 1c...Seal lip, 4...Reinforcement ring.

Claims (1)

[Scope of utility model registration request] It consists of a rubber cylindrical body consisting of an outer peripheral part 1a that is press-fitted into a hole for electric wires that communicates the inside and outside of the machine frame, and an inner peripheral part 1b into which an electric circuit is inserted. A metal reinforcing ring 4 is included in a portion corresponding to the hole, and is inserted into the inner peripheral portion 1b at a predetermined distance from the reinforcing ring 4 in the axial direction of the cylindrical body and outward of the machine frame. A rubber grommet formed locally with an annular sealing lip 1c having an inner diameter smaller than the outer diameter of the electric circuit.