Spark plug sheath temperature field detection structure

Abstract

The utility model relates to the technical field of natural gas engines, in particular to a spark plug sheath temperature field detection structure, which comprises an engine cylinder cover (1). A spark plug (2) is arranged in the engine cylinder cover (1); a sheath (3) is arranged on the spark plug (2); the sheath (3) is provided with a temperature measurement structure. The sparking plug generates high temperature during working and transmits the high temperature to a sheath arranged on the outer side of the sparking plug; the sheath is connected with a temperature measuring structure, and the temperature measuring structure can accurately and comprehensively measure the temperature of the sheath when the engine operates under different working conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of natural gas engines, and specifically, the utility model relates to a temperature field detection structure for a spark plug sheath. Background Technique

[0002] A natural gas engine is an important internal combustion engine. The temperature field generated on the spark plug sheath during its operation is an important factor affecting its operating performance. If the temperature of the spark plug sheath is too high, it will cause the spark plug sheath to sinter with the spark plug, resulting in a failure of the spark plug to fire. Therefore, understanding the temperature field and its temperature distribution of the spark plug sheath of a natural gas engine is of great significance for improving the performance of the natural gas engine. The existing spark plug sheath does not have the function of detecting the temperature field of the engine spark plug sheath.

[0003] After retrieval by the applicant, it is found that the Chinese patent document with the publication number 214227353U discloses a spark plug protective sleeve and a spark plug on September 17, 2021, including a protective sleeve body, a fixing ring, and a spark plug body. A protection head is fixedly installed on the surface of one side of the protective sleeve body, and the spark plug body is movably installed inside the protection head. This device also cannot solve the above technical problems.

[0004] Therefore, in order to improve or solve at least one of the above problems, it is necessary to optimize the existing structure of the spark plug protective sleeve. Content of the Utility Model

[0005] The purpose of the utility model is to provide a temperature field detection structure for a spark plug sheath that can realize the detection of the temperature field of the engine spark plug sheath.

[0006] To solve the above technical problems, the technical solution adopted by the utility model is: a temperature field detection structure for a spark plug sheath, including an engine cylinder head; a spark plug is provided in the engine cylinder head; a sheath is provided on the spark plug; a temperature measurement structure is provided on the sheath.

[0007] The temperature measurement structure includes a thermocouple sensor; the thermocouple sensors are respectively arranged on the inner side and the outer side of the sheath.

[0008] A first installation groove is provided on the outer wall of the sheath, and a second installation groove is provided on the inner side of the sheath; the first installation groove communicates with the second installation groove; the thermocouple sensors are respectively arranged in the first installation groove and the second installation groove.

[0009] The sheath includes a connection section and a protection section.

[0010] The spark plug includes an electrode end and a ceramic end; the electrode end is connected in the connection section, and the ceramic end is connected in the protection section.

[0011] The connecting section is provided with threaded holes; the electrode end is provided with external threads, and the threaded holes are provided with internal threads that cooperate with the external threads.

[0012] The protective section is provided with a cavity; the ceramic end is arranged in the cavity.

[0013] The engine cylinder head is provided with a bottom hole; the connecting section is arranged in the bottom hole; the end of the electrode end extends out of the threaded hole.

[0014] The first installation groove is arranged along the outer wall of the connecting section; the second installation groove is arranged on the inner wall of the protective section; the thermocouple sensors are respectively arranged in the first installation groove and the second installation groove.

[0015] The sheath is in interference fit with the bottom hole; glue is provided between the thermocouple sensors and the first installation groove and the second installation groove respectively.

[0016] The beneficial effects of this application are as follows:

[0017] 1. According to the need, this application installs thermocouple sensors at the positions for measuring the temperature field of the spark plug sheath, and installs the spark plug sheath equipped with thermocouple sensors on the engine cylinder head to operate under different working conditions. The electromotive force of the thermocouple sensors on the sheath will change due to temperature (the temperature measurement principle of the thermocouple sensors is based on measuring the electromotive force between the connection points of the measurement wires. The relationship between this electromotive force and the temperature difference is known, so the temperature can be determined according to the voltage output of the thermocouple sensors). Finally, the temperature of the spark plug sheath is measured in real time under different working conditions of the engine.

[0018] 2. When the spark plug is working, it will generate high temperature and conduct the temperature to the sheath connected on the outside; this application is provided with a first installation groove on the outer wall of the sheath close to the bottom hole of the cylinder head, and a second installation groove on the inner wall of the sheath close to the ceramic end of the spark plug. The thermocouple sensors are respectively arranged in the first installation groove and the second installation groove, and can comprehensively and accurately detect the temperature of each part of the sheath. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following further details the specific implementation manners of the present utility model in conjunction with the drawings, where:

[0020] Figure 1 is a cross-sectional view of the sheath of the temperature field detection structure of this spark plug sheath.

[0021] Figure 2 is a schematic diagram of the installation state of the sheath of the temperature field detection structure of this spark plug sheath.

[0022] Figure 3It is a diagram showing the temperature change of each cylinder's sheath under different knocking conditions (calibration points).

[0023] The markings in the above diagrams are all as follows:

[0024] The markings in the diagram are:

[0025] 1. Engine cylinder head, 101. Bottom hole,

[0026] 2. Spark plug, 201. Electrode end, 202. Ceramic end,

[0027] 3. Sheath, 301. Connection section, 302. Protection section, 303. Threaded hole, 304. Cavity,

[0028] 4. First installation groove, 401. Second installation groove,

[0029] 5. Thermocouple sensor, Specific implementation manners

[0030] Next, with reference to the accompanying drawings, through the description of the embodiments, the specific implementation manners of the present utility model will be further described in detail. The purpose is to help those skilled in the art have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present utility model, and to facilitate its implementation.

[0031] Figure 1 The shown spark plug sheath temperature field detection structure includes an engine cylinder head 1; a spark plug 2 is provided in the engine cylinder head 1; a sheath 3 is provided on the spark plug 2; and a temperature measurement structure is provided on the sheath 3.

[0032] When the spark plug 2 is working, it generates high temperature and conducts the high temperature to the sheath 3 provided outside the spark plug 2; a temperature measurement structure is connected to the sheath 3, and the temperature measurement structure can accurately and comprehensively measure the temperature of the sheath 3 when the engine is operating under different working conditions.

[0033] The temperature measurement structure includes a thermocouple sensor 5; the thermocouple sensor 5 is respectively provided on the inner side and the outer side of the sheath 3.

[0034] Connecting the thermocouple sensor 5 to both the inner side and the outer side of the sheath 3 simultaneously can achieve comprehensive and accurate temperature measurement of the entire sheath 3; the thermocouple sensor 5 has a wide measurement range, fast response speed, high mechanical strength, good stability and low cost; it is more suitable for this device.

[0035] A first installation groove 4 is provided on the outer wall of the sheath 3, and a second installation groove 401 is provided on the inner side of the sheath 3; the first installation groove 4 is communicated with the second installation groove 401; the thermocouple sensor 5 is respectively provided in the first installation groove 4 and the second installation groove 401.

[0036] The outer side of the sheath 3 is copper-plated, which can effectively conduct heat to the spark plug 2; the engine cylinder head 1 is provided with a water layer on the outer side of the sheath 3, which can cool the sheath 3; the wall thickness of the sheath 3 is 2 mm, and the depths of both the first installation groove 4 and the second installation groove 401 are 1 mm; the thermocouple sensors 5 are respectively arranged in the first installation groove 4 and the second installation groove 401, which can comprehensively and accurately detect the temperatures of various parts of the sheath 3.

[0037] The sheath 3 includes a connecting section 301 and a protecting section 302.

[0038] The connecting section 301 and the protecting section 302 are of an integral structure; the spark plug 2 is sleeved in the connecting section 301, and the connecting section 301 is sleeved in the bottom hole 101 of the engine cylinder head 1, thereby realizing the installation operations of the spark plug 2, the sheath 3 and the engine cylinder head 1.

[0039] The spark plug 2 includes an electrode end 201 and a ceramic end 202; the electrode end 201 is connected in the connecting section 301, and the ceramic end 202 is connected in the protecting section 302.

[0040] The electrode end 201 and the ceramic end 202 are of an integral structure; the electrode end 201 is fixedly connected in the connecting section 301, thereby realizing the fixing operation of the spark plug 2; the ceramic end 202 is sleeved inside the protecting section 302, and the protecting section 302 can provide effective protection for the ceramic end 202.

[0041] The connecting section 301 is provided with a threaded hole 303; the electrode end 201 is provided with an external thread, and the threaded hole 303 is provided with an internal thread that mates with the external thread.

[0042] The electrode end 201 is threadedly connected in the threaded hole 303 of the connecting section 301; the threaded connection can provide a reliable connection, can resist vibration and impact, and maintain the stability of the connection between the two; and it is convenient for the installation and disassembly of the two.

[0043] The protecting section 302 is provided with a cavity 304; the ceramic end 202 is arranged in the cavity 304.

[0044] The ceramic end 202 is sleeved in the cavity 304; the ceramic end 202 uses ceramic material, which has good high-temperature resistance and electrical insulation, but the brittleness of the ceramic is relatively large; the protecting section 302 can effectively protect the ceramic end 202 from being impacted and broken by the engine cylinder head 1; and the engine cylinder head 1 is provided with a water layer on the outer side of the sheath 3, and the protecting section 302 can separate the water layer from the spark plug 2.

[0045] The engine cylinder head 1 is provided with a bottom hole 101; the connecting section 301 is arranged in the bottom hole 101; the end of the electrode end 201 extends out of the threaded hole 303.

[0046] The electrode end 201 extends out of the threaded hole 303 to perform a sparking operation in the engine block.

[0047] The first installation groove 4 is arranged along the outer wall of the connection section 301; the second installation groove 401 is arranged on the inner wall of the protection section 302; the thermocouple sensors 5 are respectively arranged in the first installation groove 4 and the second installation groove 401.

[0048] The first installation groove 4 is arranged close to the electrode end 201 of the spark plug 2. Sparking operation is performed at the electrode end 201 of the spark plug 2, and the temperature is relatively high; and the temperature is conducted to the outer wall of the connection section 301, and the thermocouple sensor 5 can accurately detect the temperature here; the second installation groove 401 is arranged on the inner wall of the protection section 302, and the thermocouple sensor 5 can detect the temperature of the protection section 302.

[0049] The sheath 3 is in interference fit with the bottom hole 101; glue is provided between the thermocouple sensors 5 and the first installation groove 4 and the second installation groove 401 respectively.

[0050] The sheath 3 is in interference fit with the bottom hole 101, and the side wall of the bottom hole 101 squeezes the sheath 3 and the spark plug 2 tightly, which can strengthen the heat conduction between the two; glue is applied in the first installation groove 4 and the second installation groove 401, and the thermocouple sensors 5 are respectively attached to the bottoms of the first installation groove 4 and the second installation groove 401. The thermocouple sensors 5 can be fixed after the glue solidifies.

[0051] The specific working process of the utility model is as follows:

[0052] The spark plug 2 is screwed into the sheath 3 through threads and fixed; then the sheath 3 is press-fitted and fixed with the bottom hole 101 of the engine cylinder head 1 in an interference fit; among them, the thermocouple sensor 5 is introduced through the first installation groove 4 and the second installation groove 401 opened in the sheath 3, and the thermocouple sensor 5 is completely attached to the bottoms of the first installation groove 4 and the second installation groove 401. Glue is applied, and the thermocouple sensor 5 is fixed after the glue solidifies;

[0053] Temperature changes of the sheaths 3 of each cylinder under different knocking conditions (calibration points),

[0054] 1. Normal external characteristic test: Test the temperature of the sheath 3 under normal external characteristics

[0055] 2. External characteristic test under mild knocking state, test the temperature of the sheath 3 under mild knocking external characteristics;

[0056] 3. External characteristic test under moderate knocking state, test the temperature of the sheath 3 under moderate knocking external characteristics;

[0057] Test results: After the engine knocks, the temperature of the sheath 3 rises significantly. After mild knocking, the temperature of the sheath 3 under relative normal performance increases by up to 22 °C at most;

[0058] The maximum temperature difference of the sheath 3 between moderate knocking and slight knocking is 5°C, which may be related to the actual knocking differences of each cylinder of the engine (due to the limitation of the number of knock sensors, only the knocking condition of the first cylinder was monitored during the test).

[0059] The temperatures of the sheath 3 of all six cylinders meet the target value requirements, indicating that the developed sheath 3 meets the operating conditions of the engine.

[0060] The above has made an exemplary description of the present utility model in conjunction with the accompanying drawings. Obviously, the specific implementation of the present utility model is not limited by the above methods. As long as various non-substantial improvements are made by adopting the method concept and technical solution of the present utility model; or without improvement, the above concept and technical solution of the present utility model are directly applied to other occasions, they are all within the protection scope of the present utility model.

Claims

1. A temperature field detection structure for a spark plug sheath, characterized in that: Including an engine cylinder head (1); a spark plug (2) is provided in the engine cylinder head (1); a sheath (3) is provided on the spark plug (2); a temperature measuring structure is provided on the sheath (3).

2. The temperature field detection structure of a spark plug sheath according to claim 1, characterized in that: The temperature measuring structure includes a thermocouple sensor (5); the thermocouple sensor (5) is respectively provided on the inner side and the outer side of the sheath (3).

3. A temperature field detection structure for a spark plug sheath according to claim 2, characterized in that: A first mounting groove (4) is provided on the outer wall of the sheath (3), and a second mounting groove (401) is provided on the inner side of the sheath (3); the first mounting groove (4) communicates with the second mounting groove (401); the thermocouple sensor (5) is respectively provided in the first mounting groove (4) and the second mounting groove (401).

4. A temperature field detection structure for a spark plug sheath according to claim 3, characterized in that: The sheath (3) includes a connecting section (301) and a protection section (302).

5. A spark plug sheath temperature field detection structure according to claim 4, characterized in that: The spark plug (2) includes an electrode end (201) and a ceramic end (202); the electrode end (201) is connected in the connecting section (301), and the ceramic end (202) is connected in the protection section (302).

6. The temperature field detection structure of a spark plug sheath according to claim 5, characterized in that: A threaded hole (303) is provided in the connecting section (301); an external thread is provided on the electrode end (201), and an internal thread matching the external thread is provided in the threaded hole (303).

7. A temperature field detection structure for a spark plug sheath according to claim 6, characterized in that: A cavity (304) is provided in the protection section (302); the ceramic end (202) is provided in the cavity (304).

8. A temperature field detection structure for a spark plug sheath according to claim 7, characterized in that: A bottom hole (101) is provided on the engine cylinder head (1); the connecting section (301) is provided in the bottom hole (101); the end of the electrode end (201) extends out of the threaded hole (303).

9. A temperature field detection structure for a spark plug sheath according to claim 8, characterized in that: The first mounting groove (4) is arranged along the outer wall of the connecting section (301); the second mounting groove (401) is provided on the inner wall of the protection section (302); the thermocouple sensor (5) is respectively provided in the first mounting groove (4) and the second mounting groove (401).

10. A spark plug sheath temperature field detection structure according to any one of claims 8-9, characterized in that: The sheath (3) is in interference fit with the bottom hole (101); glue is provided between the thermocouple sensor (5) and the first mounting groove (4) and the second mounting groove (401) respectively.

Images