CN221196222U - Electromagnetic valve for engine - Google Patents

Abstract

The utility model provides an electromagnetic valve for an engine, which relates to the technical field of electromagnetic valves and comprises the following components: a solenoid valve main body; the rear end face of the electromagnetic valve main body is fixedly connected with a connecting plate; two connecting ends are symmetrically and fixedly connected to the outer part of the electromagnetic valve main body; two fixing seats are symmetrically and fixedly connected to the outer parts of the two connecting ends; a sliding seat is connected in the four fixed seats in a sliding way; the inner sides of the four sliding seats are fixedly connected with a mounting clamping block; an air pipe joint is arranged at the outer sides of the two connecting ends; the two installation clamping blocks on the same side are aligned with the positions of the two air pipe joints respectively. Toggle the sliding seat and then make two installation fixture blocks closed press from both sides the air pipe joint tightly through a series of transmissions to make spacing fixture block carry out spacing fixedly to the air pipe joint in to inserting spacing draw-in groove, solved at the in-process of air pipe work, because the change of air current pressure can take place to rock, lead to the air pipe joint junction to take place not hard up problem.

Description

Electromagnetic valve for engine

Technical Field

The utility model relates to the technical field of electromagnetic valves, in particular to an electromagnetic valve for an engine.

Background

In order to ensure that the emission of an engine reaches the standard in the use process of an automobile engine, an electromagnetic valve is usually arranged on the engine to control the air inlet pressure of the engine so as to reduce the fuel consumption of a vehicle, the conventional electromagnetic valve is usually composed of an electromagnetic valve main body and an air pipe joint, and after the electromagnetic valve main body is arranged in the use process, the air pipe joint is only required to be fixed on an air inlet end and an air outlet end of the electromagnetic valve main body through a clamp.

For example: the utility model with the application number of CN202221997369.0 discloses a solenoid valve for an internal combustion engine, which comprises a solenoid valve body, wherein an air inlet is formed in the lower end of one side of the solenoid valve body, an air outlet is formed in the lower end of the other side of the solenoid valve body, a protective shell is arranged outside the solenoid valve body, the lower end of the solenoid valve body is fixedly connected with the protective shell, the solenoid valve further comprises a double-thread transmission rod, the double-thread transmission rod is rotationally arranged in the air inlet, two sides of the double-thread transmission rod are respectively provided with a movable plate through threaded rotation, one end of the movable plate is fixedly welded with a shielding block, a rotating rod is rotationally arranged above the double-thread transmission rod, one end of the double-thread transmission rod penetrates through and extends to the outside of the air inlet, and the rotating rod is in transmission connection with the double-thread transmission rod through a coupling. The electromagnetic valve for the internal combustion engine can control the inlet charge to realize better organization of the inlet vortex by manually adjusting the inlet flow of the electromagnetic valve.

However, regarding the conventional solenoid valve at present, when connecting the trachea, use the clamp to fix the tracheal junction to the inlet end and the outlet end of solenoid valve main part usually, but at the in-process of tracheal work, because the change of air current pressure can take place to rock, make the tracheal junction that passes through the clamp fixed loose easily in the past, lead to the junction of solenoid valve and tracheal junction to take place to leak gas, influence the normal use of solenoid valve.

Disclosure of utility model

In view of the above, the present utility model provides an electromagnetic valve for an engine, which has an installation fixture block capable of rapidly fixing and limiting an air pipe joint, after the air pipe joint is positioned, a worker can toggle a sliding seat, slide the sliding seat in a fixing seat and stretch a supporting spring, a rack frame drives a transmission gear to rotate along with the movement of the sliding seat, and the rack frame on the other side is driven to move through the rotation of the transmission gear, so that when the sliding seat on one end is toggled to move, the sliding seat on the other side moves towards the center, the two installation fixture blocks are slowly closed along with the movement of the two sliding seats, a positioning plug block is inserted into the installation fixture block on the left part in the closing process of the two installation fixture blocks, and a connecting fixture block is clamped into a connecting fixture groove, so that the two closed installation fixture blocks are fixed, and the limiting fixture groove is exactly aligned with the position of the limiting fixture block, and when the two installation fixture blocks are completely closed, the limiting fixture block is inserted into the limiting fixture groove so as to limit and fix the air pipe joint, and the air pipe joint is prevented from loosening.

The utility model provides an electromagnetic valve for an engine, which specifically comprises the following components: a solenoid valve main body; the rear end face of the electromagnetic valve main body is fixedly connected with a connecting plate; two connecting ends are symmetrically and fixedly connected to the outer part of the electromagnetic valve main body; two fixing seats are symmetrically and fixedly connected to the outer parts of the two connecting ends; a sliding seat is connected in the four fixed seats in a sliding way; the inner sides of the four sliding seats are fixedly connected with a mounting clamping block; an air pipe joint is arranged at the outer sides of the two connecting ends; the two mounting clamping blocks on the same side are aligned with the positions of the two air pipe joints respectively; the top end surfaces of the left connecting ends are fixedly connected with a mounting plate; an auxiliary block is arranged at the right part of the mounting plate.

Optionally, a double-ended screw rod is rotatably connected in the middle of the left connecting end; the screw threads at the two ends of the double-head screw rod are opposite in rotation direction; the top end surface of the double-end screw rod is fixedly connected with an operation handle.

Optionally, two lifting frames are symmetrically connected with the outer part of the double-head screw rod through threads; the tail ends of the two lifting frames are fixedly connected with a spoiler; the two spoilers are both connected in the left connecting end in a sliding way.

Optionally, a fixed sliding rod is slidably connected to the operating handle; the lower part of the fixed slide bar is fixedly connected with an auxiliary spring; the tail end of the auxiliary spring is fixedly connected to the bottom end surface of the operating handle; the top end of the connecting end is provided with a group of fixed slots in an annular array shape; the bottom end surface of the fixed slide bar is fixedly connected with a fixed insertion block; the fixed plug block is inserted into the fixed slot

Optionally, a sliding plate is fixedly connected with the bottom end surface of the auxiliary block; the sliding plate is connected in the left connecting end in a sliding way; a filter screen is arranged in the sliding plate.

Optionally, a connecting plug rod is slidably connected to the mounting plate; two connecting springs are symmetrically and fixedly connected to the right part of the connecting inserted link; the tail ends of the two connecting springs are fixedly connected to the left end face of the mounting plate; the tail end of the connecting inserted rod is inserted into the auxiliary block.

Optionally, a positioning inserted rod is inserted into the connecting inserted rod; the upper part of the auxiliary block is connected with a sliding frame in a sliding way; the bottom end surface of the sliding frame is fixedly connected with a fixed spring; the tail end of the fixed spring is fixedly connected to the top end surface of the auxiliary block; the positioning inserted link is fixedly connected to the bottom end surface of the sliding frame.

Optionally, a group of limiting sliding grooves are formed in the outer sides of the two connecting ends; a group of auxiliary plates are fixedly connected to the outer parts of the two air pipe joints; the inner sides of the two groups of auxiliary plates are fixedly connected with a group of limit sliding racks; the two groups of limit sliding racks are respectively and slidably connected in the two groups of limit sliding grooves.

Optionally, the outer sides of the four sliding seats are fixedly connected with a supporting spring; the tail ends of the four supporting springs are respectively fixedly connected in the four fixing seats; the bottom end surfaces of the four sliding seats are fixedly connected with a rack; the four racks are respectively and slidably connected in the four fixing seats; the lower parts of the two connecting ends are respectively and rotatably connected with a transmission gear; the two racks on the same side are respectively meshed with the two transmission gears.

Optionally, the inner sides of the two mounting clamping blocks at the right part are fixedly connected with a positioning inserting block; the two positioning inserting blocks are respectively inserted into the two left mounting clamping blocks; the outer parts of the two mounting clamping blocks at the left part are respectively provided with a connecting clamping groove; a connecting clamping block is connected in the two positioning inserting blocks in a sliding manner; the tail ends of the two connecting clamping blocks are fixedly connected with a reset spring; the tail ends of the two reset springs are respectively and fixedly connected in the two positioning inserting blocks; the two connecting clamping blocks are respectively clamped in the two connecting clamping grooves; the inner sides of the four mounting clamping blocks are fixedly connected with a limiting clamping block in the middle; two limit clamping grooves are symmetrically formed in the outer portions of the two air pipe connectors.

Advantageous effects

When the air pipe is connected with the electromagnetic valve, the air pipe connector is inserted into the connecting end, the limiting sliding frame is inserted into the limiting sliding groove, then the air pipe connector is rotated to enable the limiting sliding frame to slide in the limiting sliding groove, the limiting sliding groove is used for limiting the limiting sliding frame, the position of the air pipe connector is further positioned, and the air pipe connector is initially installed, so that the operation is simple and quick.

After the positioning of the air pipe joint is finished, a worker only needs to toggle the sliding seat, then two installation clamping blocks are closed to clamp the air pipe joint through a series of transmission, the closed installation clamping blocks are automatically fixed, after the two installation clamping blocks are closed, the limiting clamping blocks are enabled to be inserted into the limiting clamping grooves to limit and fix the air pipe joint, the air pipe joint is effectively prevented from loosening, air leakage of the electromagnetic valve in the using process is avoided, the electromagnetic valve is more convenient to use, and the practicability of the electromagnetic valve for an engine is improved.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present utility model, the drawings of the embodiments will be briefly described below.

In the drawings:

FIG. 1 is a schematic diagram of an axial structure of the present utility model.

Fig. 2 is a schematic cross-sectional view of the connection end of the present utility model.

Fig. 3 is an enlarged schematic view of the structure of fig. 2 at a in accordance with the present utility model.

FIG. 4 is a schematic diagram of a cross-sectional isometric structure of a connecting end of the present utility model.

Fig. 5 is an enlarged schematic view of the structure of fig. 4 at B according to the present utility model.

Fig. 6 is a schematic diagram of an axial structure of an air tube connector according to the present utility model.

FIG. 7 is a schematic diagram of an axial structure of a connection end of the present utility model.

Fig. 8 is an enlarged schematic view of the structure of fig. 7 at C according to the present utility model.

List of reference numerals

1. A solenoid valve main body; 101. a connecting plate; 102. a connection end; 103. a double-ended screw; 104. an operating handle; 105. a lifting frame; 106. a spoiler; 107. fixing the slide bar; 108. fixing the insert block; 109. an auxiliary spring; 110. a fixed slot; 111. a sliding plate; 112. a mounting plate; 113. connecting the inserted link; 114. a connecting spring; 115. a carriage; 116. a fixed spring; 117. positioning the inserted link; 118. limiting sliding grooves; 119. an air pipe joint; 120. an auxiliary plate; 121. limiting sliding frame; 122. a limit clamping groove; 123. a fixing seat; 124. a sliding seat; 125. a support spring; 126. a rack; 127. a transmission gear; 128. installing a clamping block; 129. a connecting clamping groove; 130. positioning the insert block; 131. connecting a clamping block; 132. a return spring; 133. a limit clamping block; 134. and an auxiliary block.

Detailed Description

In order to make the objects, aspects and advantages of the technical solution of the present utility model more clear, the technical solution of the embodiment of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiment of the present utility model. Unless otherwise indicated, terms used herein have the meaning common in the art. Like reference numerals in the drawings denote like parts.

Embodiment one:

An electromagnetic valve for an engine, as shown in fig. 1 to 5, includes: a solenoid valve body 1;

The rear end face of the electromagnetic valve main body 1 is fixedly connected with a connecting plate 101; two connecting ends 102 are symmetrically and fixedly connected to the outer part of the electromagnetic valve main body 1; two fixing seats 123 are symmetrically and fixedly connected to the outer parts of the two connecting ends 102; a sliding seat 124 is slidably connected in each of the four fixing seats 123; a mounting fixture 128 is fixedly connected to the inner sides of the four sliding seats 124; an air pipe joint 119 is arranged on the outer sides of the two connecting ends 102; the two mounting fixtures 128 on the same side are aligned with the positions of the two air pipe joints 119 respectively; the top end surfaces of the left connecting ends 102 are fixedly connected with a mounting plate 112; the right portion of the mounting plate 112 is provided with an auxiliary block 134.

A double-ended screw 103 is rotatably connected in the middle of the left connecting end 102; the threads at the two ends of the double-ended screw 103 are opposite in rotation direction; the top end surface of the double-headed screw 103 is fixedly connected with an operation handle 104.

Two lifting frames 105 are symmetrically connected with the outer part of the double-head screw 103 through threads; the tail ends of the two lifting frames 105 are fixedly connected with a spoiler 106; both spoilers 106 are slidably coupled within the left link 102.

A fixed slide bar 107 is connected in a sliding way to the operation handle 104; an auxiliary spring 109 is fixedly connected to the lower part of the fixed slide bar 107; the tail end of the auxiliary spring 109 is fixedly connected to the bottom end surface of the operation handle 104; the top end surface of the connecting end 102 is provided with a group of fixed slots 110 in an annular array shape; the bottom end surface of the fixed slide bar 107 is fixedly connected with a fixed insertion block 108; the fixed plug 108 is plugged into the fixed slot 110.

The bottom end surface of the auxiliary block 134 is fixedly connected with a sliding plate 111; the sliding plate 111 is slidably connected within the left connecting end 102; a filter screen is provided in the slide plate 111.

A connecting plug 113 is slidably connected to the mounting plate 112; two connecting springs 114 are symmetrically and fixedly connected to the right part of the connecting inserted rod 113; the tail ends of the two connecting springs 114 are fixedly connected to the left end face of the mounting plate 112; the end of the connecting rod 113 is inserted into the auxiliary block 134.

A positioning plunger 117 is inserted into the connecting plunger 113; the upper part of the auxiliary block 134 is slidably connected with a sliding frame 115; the bottom end surface of the sliding frame 115 is fixedly connected with a fixed spring 116; the tail end of the fixed spring 116 is fixedly connected to the top end surface of the auxiliary block 134; the positioning plunger 117 is fixedly connected to the bottom end surface of the carriage 115.

A group of limiting sliding grooves 118 are formed on the outer sides of the two connecting ends 102; a group of auxiliary plates 120 are fixedly connected to the outer parts of the two air pipe joints 119; a group of limiting sliding frames 121 are fixedly connected to the inner sides of the two groups of auxiliary plates 120; the two sets of limit carriages 121 are slidably coupled within the two sets of limit runners 118, respectively.

Specific use and action of the embodiment: by rotating the operation handle 104, the operation handle 104 drives the double-end screw 103 to rotate, only the spoiler 106 is arranged in the connecting end 102 of the air inlet, the spoiler 106 is not arranged in the connecting end 102 of the air outlet, the lifting frame 105 is driven to move in opposite directions in the process of rotating the double-end screw 103, the two spoilers 106 are driven to move in opposite directions in the process of moving the lifting frame 105 in opposite directions, the air inlet is blocked by the two spoilers 106 moving in opposite directions, the air inflow at the air inlet of the electromagnetic valve is convenient for a worker to manually adjust, when the operation handle 104 needs to be rotated, the worker needs to pull the fixed slide bar 107 firstly, so that the fixed slide bar 107 slides in the operation handle 104 and extrudes the auxiliary spring 109, the fixed insert block 108 is separated from the fixed slot 110 along with the sliding of the fixed slide bar 107, at this time, the operator can rotate the operating handle 104 to adjust the air inflow, after the adjustment is completed, the operator only needs to loosen the fixed slide bar 107 to reset the fixed slide bar 107 along with the rebound of the auxiliary spring 109, so that the fixed insert block 108 is inserted into the fixed slot 110 aligned with the fixed insert block to limit the operating handle 104, the air entering the electromagnetic valve main body 1 can be filtered through the filter screen on the sliding plate 111, the medium in the air is blocked, the service life of the electromagnetic valve main body 1 is prolonged, the auxiliary block 134 is limited through the connecting insert rod 113, the sliding plate 111 is further limited and fixed, when the filter screen needs to be replaced, the operator pulls the connecting insert rod 113 to slide the connecting insert rod 113 in the auxiliary block 134 and stretch the connecting spring 114, when the connecting insert rod 113 is completely separated from the auxiliary block 134, the sliding plate 111 can be taken out to replace the filter screen, when the positioning inserting rod 117 is inserted into the connecting inserting rod 113, the connecting inserting rod 113 cannot be pulled, when the filter screen needs to be replaced, a worker needs to pull the positioning inserting rod 117 firstly to separate from the connecting inserting rod 113, limiting of the connecting inserting rod 113 is released, meanwhile, the connecting inserting rod 113 can be prevented from loosening through limiting of the connecting inserting rod 113 by the positioning inserting rod 117, when the electromagnetic valve main body 1 is used, the worker can install the electromagnetic valve main body 1 into an engine through the connecting plate 101, then the air pipe joint 119 is inserted into the connecting end 102, the limiting sliding frame 121 is inserted into the limiting sliding groove 118, then the air pipe joint 119 is rotated to enable the limiting sliding frame 121 to slide in the limiting sliding groove 118, the limiting sliding groove 118 is used for limiting the limiting sliding frame 121, and then the position of the air pipe joint 119 is located.

Embodiment two:

On the basis of the first embodiment, as shown in fig. 6 to 8, there are: the device comprises a limiting clamping groove 122, a supporting spring 125, a rack 126, a transmission gear 127, a connecting clamping groove 129, a positioning inserting block 130, a connecting clamping block 131, a reset spring 132 and a limiting clamping block 133, wherein the outer sides of four sliding seats 124 are fixedly connected with the supporting spring 125; the tail ends of the four supporting springs 125 are respectively fixedly connected in the four fixing seats 123; a rack 126 is fixedly connected to the bottom end surfaces of the four sliding seats 124; the four racks 126 are respectively slidably connected in the four fixing seats 123; the lower parts of the two connecting ends 102 are rotatably connected with a transmission gear 127; the two racks 126 on the same side are engaged with two transmission gears 127, respectively.

A positioning insert block 130 is fixedly connected to the inner sides of the two right mounting clamping blocks 128; the two positioning inserting blocks 130 are respectively inserted into the two left mounting clamping blocks 128; the outer parts of the two left mounting clamping blocks 128 are respectively provided with a connecting clamping groove 129; a connecting fixture block 131 is slidably connected in each of the two positioning plug blocks 130; the tail ends of the two connecting clamping blocks 131 are fixedly connected with a reset spring 132; the tail ends of the two return springs 132 are respectively fixedly connected in the two positioning plug blocks 130; the two connecting clamping blocks 131 are respectively clamped in the two connecting clamping grooves 129; the inner sides of the four mounting clamping blocks 128 are fixedly connected with a limiting clamping block 133 in the middle; two limiting clamping grooves 122 are symmetrically formed in the outer portions of the two air pipe connectors 119.

Specific use and action of the embodiment: after the air pipe joint 119 is positioned, a worker can stir the sliding seat 124, so that the sliding seat 124 slides in the fixed seat 123 and stretches the supporting spring 125, the rack 126 drives the transmission gear 127 to rotate along with the movement of the sliding seat 124, the rack 126 on the other side is driven to move through the rotation of the transmission gear 127, when the sliding seat 124 at one end is stirred to move, the sliding seat 124 on the other side can move towards the center, two installation clamping blocks 128 can be slowly closed along with the movement of the two sliding seats 124, the positioning inserting block 130 can be inserted into the left installation clamping block 128 in the closing process of the two installation clamping blocks 128, the connecting clamping block 131 is clamped into the connecting clamping groove 129, the two installation clamping blocks 128 are fixed, the limiting clamping groove 122 is just aligned with the position of the limiting clamping block 133 after the air pipe joint 119 is positioned, the limiting clamping block 133 can be inserted into the limiting clamping groove 122 to limit and fix the air pipe joint 119, and the air pipe joint 119 is prevented from loosening.

Claims (10)

1. An electromagnetic valve for an engine, comprising: a solenoid valve body (1); the rear end face of the electromagnetic valve main body (1) is fixedly connected with a connecting plate (101); two connecting ends (102) are symmetrically and fixedly connected to the outside of the electromagnetic valve main body (1); the connecting device is characterized in that the outer parts of the two connecting ends (102) are symmetrically and fixedly connected with two fixing seats (123); a sliding seat (124) is slidably connected in each of the four fixed seats (123); the inner sides of the four sliding seats (124) are fixedly connected with a mounting clamping block (128); an air pipe joint (119) is arranged on the outer sides of the two connecting ends (102); the two mounting clamping blocks (128) on the same side are aligned with the positions of the two air pipe joints (119) respectively; the top end surfaces of the connecting ends (102) at the left part are fixedly connected with a mounting plate (112); an auxiliary block (134) is arranged at the right part of the mounting plate (112).

2. An electromagnetic valve for an engine as set forth in claim 1, wherein: a double-head screw rod (103) is rotatably connected in the middle of the left connecting end (102); the screw threads at the two ends of the double-end screw rod (103) are opposite in rotation direction; the top end surface of the double-end screw rod (103) is fixedly connected with an operation handle (104).

3. An electromagnetic valve for an engine as set forth in claim 2, wherein: two lifting frames (105) are symmetrically connected with the outer part of the double-head screw rod (103) through threads; the tail ends of the two lifting frames (105) are fixedly connected with a spoiler (106); both spoilers (106) are slidably coupled within the left link (102).

4. An electromagnetic valve for an engine as set forth in claim 2, wherein: the operation handle (104) is connected with a fixed sliding rod (107) in a sliding way; the lower part of the fixed slide bar (107) is fixedly connected with an auxiliary spring (109); the tail end of the auxiliary spring (109) is fixedly connected to the bottom end surface of the operating handle (104); the top end surface of the connecting end (102) is provided with a group of fixed slots (110) in an annular array shape; the bottom end surface of the fixed slide bar (107) is fixedly connected with a fixed insertion block (108); the fixed plug block (108) is inserted into the fixed slot (110).

5. An electromagnetic valve for an engine as set forth in claim 1, wherein: the bottom end surface of the auxiliary block (134) is fixedly connected with a sliding plate (111); the sliding plate (111) is connected in the left connecting end (102) in a sliding way; a filter screen is arranged in the sliding plate (111).

6. An electromagnetic valve for an engine as set forth in claim 1, wherein: a connecting inserted rod (113) is connected in a sliding manner to the mounting plate (112); two connecting springs (114) are symmetrically and fixedly connected to the right part of the connecting inserted rod (113); the tail ends of the two connecting springs (114) are fixedly connected to the left end face of the mounting plate (112); the tail end of the connecting inserted rod (113) is inserted into the auxiliary block (134).

7. An electromagnetic valve for an engine as set forth in claim 6, wherein: a positioning inserted rod (117) is inserted into the connecting inserted rod (113); the upper part of the auxiliary block (134) is connected with a sliding frame (115) in a sliding way; the bottom end surface of the sliding frame (115) is fixedly connected with a fixed spring (116); the tail end of the fixed spring (116) is fixedly connected with the top end surface of the auxiliary block (134); the positioning inserted rod (117) is fixedly connected to the bottom end surface of the sliding frame (115).

8. An electromagnetic valve for an engine as set forth in claim 1, wherein: a group of limiting sliding grooves (118) are formed in the outer sides of the two connecting ends (102); a group of auxiliary plates (120) are fixedly connected to the outer parts of the two air pipe joints (119); the inner sides of the two groups of auxiliary plates (120) are fixedly connected with a group of limit sliding frames (121); the two groups of limiting sliding racks (121) are respectively and slidably connected in the two groups of limiting sliding grooves (118).

9. An electromagnetic valve for an engine as set forth in claim 1, wherein: the outer sides of the four sliding seats (124) are fixedly connected with a supporting spring (125); the tail ends of the four supporting springs (125) are respectively and fixedly connected in the four fixing seats (123); the bottom end surfaces of the four sliding seats (124) are fixedly connected with a rack (126); the four racks (126) are respectively and slidably connected in the four fixing seats (123); the lower parts of the two connecting ends (102) are respectively and rotatably connected with a transmission gear (127); the two racks (126) on the same side are respectively meshed with two transmission gears (127).

10. An electromagnetic valve for an engine as set forth in claim 1, wherein: the inner sides of the two mounting clamping blocks (128) at the right part are fixedly connected with a positioning inserting block (130); the two positioning inserting blocks (130) are respectively inserted into the two left mounting clamping blocks (128); the outer parts of the two mounting clamping blocks (128) at the left part are respectively provided with a connecting clamping groove (129); a connecting clamping block (131) is connected in the two positioning inserting blocks (130) in a sliding manner; the tail ends of the two connecting clamping blocks (131) are fixedly connected with a reset spring (132); the tail ends of the two reset springs (132) are respectively and fixedly connected in the two positioning plug blocks (130); the two connecting clamping blocks (131) are respectively clamped in the two connecting clamping grooves (129); the inner sides of the four mounting clamping blocks (128) are fixedly connected with a limiting clamping block (133) in the middle; two limiting clamping grooves (122) are symmetrically formed in the outer portions of the two air pipe connectors (119).