CN112014029A - Knock sensor and manufacturing process thereof - Google Patents

Abstract

The invention relates to a knock sensor and a manufacturing process thereof, the knock sensor comprises a base, piezoelectric ceramics are arranged in the base, the knock sensor is characterized in that a plane mounting surface is arranged in the base, the plane mounting surface is connected with a copper sheet welded with the piezoelectric ceramics, the end part of the base is connected with a plastic support, a sealing connection assembly is arranged between the plastic support and the base, a conductive spring is linked between the piezoelectric ceramics and the plastic support, and a conductive assembly is arranged in the plastic support, the knock sensor has the beneficial effects that: the knock sensor and the manufacturing process thereof are provided, the internal structure is improved, welding spots are reduced, the production process is simplified, and the production efficiency is improved.

Description

A knock sensor and its manufacturing process

technical field

The invention relates to the technical field of knock sensors, in particular to a knock sensor and a manufacturing process thereof.

Background technique

Knock is a phenomenon of abnormal combustion when the engine is running. When the gasoline engine knocks, in the process of flame propagation in the combustion chamber of the gasoline engine, the unburned mixture far from the spark plug is compressed by the expansion of the burned mixture, and the local temperature here exceeds the self-ignition temperature of the fuel due to thermal radiation. Spontaneous reaction to form one or more flame cores, where the terminal mixture ignites and burns before the normal flame spreads. This self-igniting combustion emits a very strong flame, which is several times or even dozens of times faster than the normal combustion flame. When the normal combustion and knocking two opposite combustion pressure waves meet, a violent gas vibration will be produced, and a unique metal impact sound will be emitted, so it is called "knock". The sound of metal hitting the engine block, and the temperature of the engine parts rises sharply, which damages engine-related parts, increases fuel consumption, and deteriorates fuel economy. The engine and body can feel vibration, and knocking will make the engine work rough. Explosion, power drop.

The knock sensor is a vibration sensor that detects the knocking state of the engine. It is installed on the engine block, converts the knock generated by the engine into an electrical signal, and transmits the electrical signal to the ECU. The knock sensor generally includes a base, Piezoelectric ceramics placed in the base, in the prior art, piezoelectric ceramics and bases generally adopt a unique welding process. This connection method, on the one hand, has many solder joints, and on the other hand, due to various aspects such as equipment and personnel The reason is that the scrap rate is high. After the welding is completed, the wiring is carried out, the structure is cumbersome, the positioning of each part is not accurate, and the processing technology is complicated.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a knock sensor and a manufacturing process thereof aiming at the deficiencies of the above-mentioned prior art.

For achieving the above object, the present invention provides the following technical solutions:

A knock sensor includes a base, and a piezoelectric ceramic is arranged in the base, wherein the base is provided with a plane mounting surface, and the plane mounting surface is connected with copper welded with the piezoelectric ceramic. The end of the base is connected with a plastic bracket, a sealing connection component is arranged between the plastic bracket and the base, a conductive spring is linked between the piezoelectric ceramic and the plastic bracket, and the plastic bracket is provided with Conductive components.

By adopting the above technical solution, copper sheets and conductive springs are arranged, and the piezoelectric ceramics can be stably fixed in the base. Compared with the prior art, no welding is required, and the production efficiency is improved. Weld through, internal unevenness problems, simplify the production process and reduce the scrap rate.

The above-mentioned knock sensor and its manufacturing process can be further configured as follows: the conductive component includes a copper gasket that is in contact and linkage with one end of the conductive spring, the copper gasket is welded to the end of the plastic bracket, and the middle of the plastic bracket is fixed. Threaded inserts.

Using the above technical solution, a copper gasket is provided to electrically connect the conductive spring and the insert for signal transmission. The copper gasket and the conductive spring can realize the external insulation and the internal circuit transmission, simplify the structure of the internal parts, and the plastic bracket is integrally injection-molded, which is easy to manufacture.

The above-mentioned knock sensor and its manufacturing process can be further configured as follows: the sealing connection component includes a gasket placed on the outer edge end face of the plastic bracket, and the plastic bracket is provided with a sealing ring on the other end face of the gasket.

The above-mentioned knock sensor and its manufacturing process can be further configured as follows: an end of the base facing the plastic bracket is provided with an abutting surface that can interfere with the gasket.

By adopting the above technical solution, the washer and the abutting surface are provided, the plastic bracket and the base can be fixedly connected, and the washer can replace the friction between the plastic bracket and the base, and prolong the service life of the base and the plastic bracket.

The above-mentioned knock sensor and its manufacturing process can be further configured as follows: several groups of bumps are evenly distributed on the outer periphery of the copper sheet.

By adopting the above technical solution, by arranging bumps on the outer periphery of the copper sheet, the tightness of the connection between the copper sheet and the base can be further enhanced.

The above-mentioned knock sensor and the manufacturing process thereof may be further configured as follows: the base is provided with a threaded connection post relative to the other end of the connecting plastic bracket.

With the above technical solution, the threaded connection column is used to connect the base and the cylinder.

The above-mentioned knock sensor and its manufacturing process can be further configured to include the following steps:

S1: blanking;

S2: prepare epoxy resin;

S3: Take a small amount of epoxy resin prepared in step S2 and apply it to the middle of the copper sheet, and place the piezoelectric ceramic in the middle of the copper sheet with a tooling to obtain a crystal copper sheet;

S4: the crystal copper sheet in step S3 is cured for 24 hours;

S5: the crystalline copper sheet after curing in step S4 is installed in the base using the bumps on the copper sheet;

S6: Solder the copper gasket in the plastic bracket by soldering and contact with the insert;

S7: install the conductive spring in the plastic bracket in step S6;

S8: place a sealing ring and a gasket on the outer peripheral surface of the plastic bracket in step S7;

S9: Put the plastic bracket in step S8 in the base, keep the conductive spring in contact with the crystal copper sheet in step S5, and perform flanging processing on the end of the base close to the plastic bracket.

S10: Quality inspection.

The above-mentioned knock sensor and its manufacturing process can be further configured as follows: the tooling belt in the S2 has a semi-automatic rotation function, which can be rotated under the condition of force so that the epoxy resin is evenly distributed at the intermediate joint of the two objects. .

With the above technical solution, the epoxy resin has high mechanical properties, excellent adhesive properties, small curing shrinkage, and good electrical properties, which is helpful for the effective combination between two different materials and ensures the stability of the output voltage; step S2 uses The tooling can control the pressing distance more precisely, and the excess glue in the middle will overflow when the force is applied. The rotation increases the distribution of glue and the discharge of air, making the two objects more firmly combined. The tooling can also control the rotation time, so that each The combination of an accessory is more standard. After curing in step S4, the piezoelectric ceramic can be firmly adhered to the surface of the copper sheet; in step S5, the crystal copper sheet can be integrated with the base, so that the induction sensitivity is faster, compared with the prior art. The processing cost of the lathe is reduced; the function of the conductive spring in step S9 is to connect the base and the plug. Compared with the direct wire connection in the prior art, the advantage is that there will be no virtual welding, and it is not easy to fall off during use.

Beneficial effects of the present invention:

By adopting the above technical solution, in terms of structure, copper sheets and conductive springs are arranged, which can stably fix the piezoelectric ceramics in the base. Compared with the prior art, no welding is required, and the production efficiency is improved, and there are no solder joints in the base. The seat will not have problems of welding penetration and internal unevenness, simplifying the production process and reducing the scrap rate; further setting plastic brackets, copper gaskets and conductive springs can realize external insulation and internal circuit transmission, simplifying the structure of internal components , and the plastic bracket is integrally injection-molded, which is easy to process and manufacture; further setting a washer and abutting surface can realize the fixed connection between the plastic bracket and the base, and the washer can replace the friction between the plastic bracket and the base, and prolong the relationship between the base and the plastic bracket. service life;

In terms of manufacturing process, compared with the prior art, there is no need for welding between the crystal copper sheet and the base, no virtual welding occurs, and it is not easy to fall off during use, and the overall assembly process is simple to operate.

The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

1 is a schematic cross-sectional view of an embodiment of the present invention;

FIG. 2 is a schematic diagram of the structure of a copper sheet according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

A knock sensor as shown in Figures 1 to 2 includes a base 1, a piezoelectric ceramic 2 is provided in the base 1, a plane mounting surface is provided in the base 1, and the plane mounting surface is connected to the There is a copper sheet 3 welded with the piezoelectric ceramics 2, the outer periphery of the copper sheet 3 is evenly distributed with several groups of bumps 31, the end of the base 1 is connected with a plastic bracket 4, the plastic bracket 4 and the base 1 are connected. A sealed connection component is arranged between the piezoelectric ceramics 2 and the plastic bracket 4, and a conductive spring 5 is linked with the plastic bracket 4. A conductive component is arranged in the plastic bracket 4. Gasket 6, the copper gasket 6 is welded to the end of the plastic bracket 4, the middle part of the plastic bracket 4 is fixedly penetrated with an insert 7, and the sealing connection assembly includes a gasket 8 placed on the outer edge of the plastic bracket 4, The plastic bracket 4 is provided with a sealing ring 9 on the other end face of the gasket 8, and the base 1 is provided with an abutment surface 10 formed by flanging and can be linked with the gasket 8 at one end facing the plastic bracket 4. The other end of the base 1 opposite to the connecting plastic bracket 4 is provided with a threaded connecting column 11 .

A manufacturing process of a knock sensor, comprising the following steps,

S1: blanking;

S2: prepare epoxy resin;

S3: Take a small amount of the epoxy resin prepared in step S2 and apply it to the middle of the copper sheet 3, and place the piezoelectric ceramic 2 in the middle of the copper sheet 3 with a tooling to obtain a crystal copper sheet 3;

S4: the crystal copper sheet 3 in step S3 is cured for 24 hours;

S5: the crystalline copper sheet 3 after curing in step S4 is installed in the base 1 by using the bumps 31 on the copper sheet 3;

S6: Weld the copper gasket 6 in the plastic bracket 4 by soldering, and contact the insert 7;

S7: install the conductive spring 5 in the plastic bracket 4 in step S6;

S8: place the sealing ring 9 and the gasket 8 on the outer peripheral surface of the plastic bracket 4 in step S7;

S9: put the plastic support 4 in step S8 in the base 1, and keep the conductive spring 5 in contact with the crystal copper sheet 3 in step S5, and perform flanging processing on the end of the base 1 close to the plastic support 4;

S10: Quality inspection.

The tooling belt in the S2 has a semi-automatic rotation function, which can be rotated under the condition of force so that the epoxy resin is evenly distributed at the intermediate joint of the two objects.

Claims (8)

1. A knock sensor, comprising a base, wherein the base is provided with piezoelectric ceramics, characterized in that: the base is provided with a plane mounting surface, and the plane mounting surface is connected to be welded with the piezoelectric ceramics. The end of the base is connected with a plastic bracket, a sealing connection component is arranged between the plastic bracket and the base, a conductive spring is linked between the piezoelectric ceramic and the plastic bracket, and the plastic bracket is Equipped with conductive components. 2 . The knock sensor according to claim 1 , wherein the conductive component comprises a copper gasket that is in contact with one end of the conductive spring, the copper gasket is welded to the end of the plastic bracket, and the plastic The middle part of the bracket is fixedly pierced with inserts. 3 . The knock sensor according to claim 1 , wherein the sealing connection assembly comprises a gasket placed on the outer edge end face of the plastic bracket, and the plastic bracket is provided with a sealing ring on the other end face of the gasket relative to the gasket. 4 . . 4 . The knock sensor according to claim 3 , wherein the end of the base facing the plastic bracket is provided with an abutting surface that can interfere with the washer. 5 . 5 . The knock sensor according to claim 1 , wherein several groups of bumps are evenly distributed on the outer periphery of the copper sheet. 6 . 6 . The knock sensor according to claim 1 , wherein the base is provided with a threaded connecting column relative to the other end of the connecting plastic bracket. 7 . 7. The manufacturing process of a knock sensor according to any one of claims 1 to 6, characterized in that: comprising the following steps: S1: blanking; S2: prepare epoxy resin; S3: Take a small amount of epoxy resin prepared in step S2 and apply it to the middle of the copper sheet, and place the piezoelectric ceramic in the middle of the copper sheet with a tooling to obtain a crystal copper sheet; S4: the crystal copper sheet in step S3 is cured for 24 hours; S5: the crystalline copper sheet after curing in step S4 is installed in the base using the bumps on the copper sheet; S6: Solder the copper gasket in the plastic bracket by soldering and contact with the insert; S7: install the conductive spring in the plastic bracket in step S6; S8: place a sealing ring and a gasket on the outer peripheral surface of the plastic bracket in step S7; S9: place the plastic bracket in step S8 in the base, keep the conductive spring in contact with the crystal copper sheet in step S5, and perform flanging processing on the end of the base close to the plastic bracket; S10: Quality inspection. 8. A knock sensor according to claim 7 and its manufacturing process, characterized in that: the tooling belt in the S2 has a semi-automatic rotation function, which can be rotated under force to make the epoxy resin evenly distributed here. The joint between two objects.

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