Knock Sensor

Technical Field

The present invention relates to a knock sensor.

Background Art

A conventional knock sensor comprises a sensor head, a sensor cable connected to the sensor head, and an injection portion. The injection portion encloses an end of the sensor and the sensor head in an injection molding manner. The end of the sensor is provided with a wire and an insulating layer positioned outside the wire. The insulating layer is manufactured using a vertical cutting method. During the process of injection molding, a high temperature transmitted by a melted resin material will cause the hardness of the material of the insulating layer to become lower. The high pressure transmitted by the melted resin material is applied to an end surface of the insulating layer, which will cause the deformation of the insulating layer material and eventually the degradation of the overall sealing performance of the knock sensor.

Summary of the Invention

The object of the present invention is to provide a knock sensor which reduces the axial tension of a sensor cable and reduces the plastic deformation of an insulating layer.

According to an aspect of the present invention, provided is a knock sensor, comprising:

a sensor head;

a sensor cable which comprises a wire electrically connected to the sensor head and an insulating layer enclosing the wire, the insulating layer comprising a first end close to the sensor head and a second end away from the sensor head; and an injection portion which is provided with an injection gate, the injection portion enclosing the first end and the sensor head in an injection molding manner, the first end being provided with a chamfer, and the injection gate being positioned in front of the chamfer.

Preferably, the chamfer is rounded or beveled.

Preferably, the chamfer is formed in a cutting manner.

Preferably, the chamfer is formed along a circle.

Preferably, the sensor cable is provided with a first central axis, and the sensor head is provided with a second central axis perpendicular to the first central axis.

Preferably, the knock sensor further comprises a connector electrically connected to the second end.

Preferably, the injection portion comprises a main body portion enclosing the sensor head and a connecting portion connected to the sensor cable, the sensor cable is provided with a first central axis, and the connecting portion comprises a contracting end that is close to the first central axis.

Preferably, the section of the contracting end in an axial direction comprises a first outer surface in a conical shape, a second outer surface, and a third outer surface in a cylindrical shape that connects the first outer surface and the second outer surface, with the second outer surface being annular in the shape of a rounded corner.

Preferably, the injection gate is located on the main body portion .

According to an aspect of the present invention, provided is a knock sensor, comprising: a sensor head;

a sensor cable which is provided with a first central axis, the sensor cable comprising a wire electrically connected to the sensor head and an insulating layer enclosing the wire; and an injection portion which is provided with an injection gate, the injection portion enclosing one end of the insulating layer and the sensor head in an injection molding manner, the insulating layer positioned in the injection portion being provided with an inclined plane inclined relative to the first central axis, and the injection gate being positioned in front of the inclined plane.

The knock sensor provided by the present invention, by arranging the chamfer on the first end of the insulating layer, can reduce the pressure caused by melted resin on an end surface of the sensor cable in the axial direction of the sensor cable when the melted resin flowing in through the injection gate flows to the chamfer .

Brief Description of the Drawings

Fig. 1 is a perspective view of a knock sensor of the present invention .

Fig. 2 is a partially exploded view of the knock sensor of the present invention.

Fig. 3 is a cross-sectional view of the knock sensor of the present invention.

Fig. 4 is an enlarged view at "A" in Fig. 3.

Detailed Description of Embodiments

Referring to Fig. 1, the present invention provides a knock sensor 100, which comprises a sensor head 1, a connector 3, a sensor cable 2 electrically connecting the connector 3 with the sensor head 1, and an injection portion 4 enclosing the ends of the sensor head 1 and the sensor cable 2. The injection portion 4 comprises a main body portion 41 enclosing the sensor head 1, and a connecting portion 42 connected to the sensor cable 2.

Referring further to Figs. 2 and 3, the sensor cable 2 comprises a wire 22 electrically connected to the sensor head 1 and an insulating layer 21 enclosing the wire 22. The insulating layer 21 comprises a first end 211 close to the sensor head 1 and a second end 212 away from the sensor head 1.

The injection portion 4 is provided with an injection gate 43. The injection portion 4 encloses the first end 211 and the sensor head 1 in an injection molding manner. The first end 211 is provided with a chamfer 2111 directly facing the injection gate 43. During injection molding, a high temperature transmitted by a melted resin material will cause the hardness of the material of the first end 211 of the insulating layer 21 to become lower. Since the chamfer 2111 directly faces the injection gate 43, when the melted resin material flows to the chamfer 2111, the pressure caused by the melted resin on the end surface of the sensor cable 2 in the axial direction of the sensor cable 2 can be reduced due to the influence of an inclined plane of the chamfer 2111, so as to achieve the purpose of eliminating the injection deformation of the sensor cable 2. Preferably, the injection gate 43 is located on the main body portion 41.

However, in this embodiment, a chamfer 2111 directly facing the injection gate 43 is provided on the first end 211. It would be known for those skilled in the art that arranging an inclined plane on the first end 211 can also meet the purpose of reducing the pressure caused by the melted resin on the end surface of the sensor cable 2 in the axial direction of the sensor cable 2. The inclined plane directly faces the injection gate 43, and when the melted resin material flowing in from the injection gate 43 flows inside a cavity, the resin material will rush onto the inclined plane. Because the inclined plane directly faces the injection gate 43, the force caused by the melted resin material on the sensor cable 2 in the axial direction can be divided into a force in the axial direction and a vertical outward force, thus reducing the force in the axial direction, and then reducing the injection deformation of the sensor cable 2.

Preferably, the chamfer 2111 may be rounded or beveled. The chamfer 2111 is formed in a cutting manner. The chamfer 2111 may also be arranged in the form of a circle.

The sensor cable 2 is provided with a first central axis LI, and the sensor head 1 is provided with a second central axis L2 perpendicular to the first central axis LI.

The knock sensor 100 further comprises the connector 3 electrically connected to the second end 212. By providing the connector 3, a signal detected by the sensor head 1 can be transmitted to a signal processing device through the connector

3.

The injection portion 4 comprises a main body portion 41 enclosing the sensor head 1, and a connecting portion 42 connected to the sensor cable 2. The sensor cable 2 is provided with a first central axis LI, and the connecting portion 42 comprises a contracting end 421 that is close to the first central axis LI. By arranging the contracting end 421 on the connecting portion 42, during injection molding, a contact area between the melted resin material and an injection cavity is increased, and a wall thickness is partially reduced with an increased contact length, thus improving the cooling efficiency of the resin and the sensor cable 2 in an injection mold.

Referring further to Fig. 4, the section of the contracting end 421 in an axial direction comprises a first outer surface 4213 in a conical shape, a second outer surface 4211, and a third outer surface 4212 in a cylindrical shape that connects the first outer surface 4213 and the second outer surface 4211. The second outer surface 4211 is annular in the shape of a rounded corner .

It will be apparent for those skilled in the art that various modifications and variations may be made to the above exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention shall encompass the modifications and variations of the present invention that fall within the scope of the appended claims and the equivalent technical solutions thereof.