Internal support test head of cylinder hydraulic test machine

Abstract

The present invention provides an internal support test head of a steel cylinder water pressure test machine, which belongs to the field of mechanical technology. It solves the problems of low working efficiency and unsatisfactory sealing effect of the internal support test head of the existing steel cylinder water pressure test machine. The internal support test head of the steel cylinder water pressure test machine comprises a fixed plate, a support tube is fixedly connected to the lower side of the fixed plate, a cylindrical internal support shaft seat is coaxially fixedly connected to the lower end of the support tube, a water injection rod is passed through the support tube, a driving member is provided on the fixed plate, an air passage is formed between the outer side of the water injection rod and the internal support shaft seat, a sealing gasket is positioned on the lower end surface of the internal support shaft seat, the lower end of the water injection rod passes through the internal support shaft seat and the sealing gasket, a cylindrical internal support block is sleeved in the middle of the water injection rod and the water injection rod can reciprocate relative to the internal support block, a conical surface is provided in the middle of the water injection rod and the conical surface can push the lower end of the internal support block to open. The internal support test head of the steel cylinder water pressure test machine has the advantages of good sealing effect and high working efficiency.

Description

Technical Field

[0001] The invention belongs to the field of mechanical technology and relates to a test head, in particular to an internal support type test head of a steel cylinder water pressure tester. Background Art

[0002] According to international and national standards, seamless steel cylinders, refillable welded cylinders, aluminum alloy seamless steel cylinders and wound cylinders must be subjected to water pressure tests, especially for liquefied petroleum gas cylinders. In the prior art, the water pressure test is carried out by manually moving a single cylinder to the test position and manually opening the water injection and gas injection valves to complete the test. The existing cylinder water pressure test equipment has the following defects: the cylinder is placed and moved away from the test position by manual movement, which is labor-intensive, time-consuming and has low output; during the test, a water injection pressure head is first placed on the plane of the cylinder valve seat, and water is injected into the cylinder. After the cylinder is filled with water, pressurization is applied, and the clamping force acts on the bottle body through the water injection pressure head. When the cylinder is pressurized and maintained, the bottle body is subjected to external force, and the cylinder is deformed due to external force, which affects the test accuracy. The above-mentioned testing equipment can only perform random inspections on the produced cylinders, so there are serious safety hazards.

[0003] For example, a steel cylinder water pressure test automatic test machine disclosed in a Chinese patent document (application number: 201410186966.9) has a structure including: a frame, an automatic bottle clamping device and a sealing rod on the frame; the sealing rod is connected to a mobile drive mechanism and a rotary drive mechanism, the mobile drive mechanism drives the sealing rod to move up and down to insert into the steel cylinder or withdraw from the inside of the steel cylinder; the rotary drive mechanism drives the sealing rod to rotate so that the sealing rod is screwed into the threaded hole of the valve seat of the steel cylinder, which is convenient for the sealing rod to be inserted into the steel cylinder to inject gas and water for water pressure test. The rotary drive mechanism of the automatic test machine drives the sealing rod to rotate, and realizes the threaded sealing connection between the sealing rod and the threaded hole of the valve seat of the steel cylinder, so its working efficiency is not high and the sealing effect is not ideal. Summary of the invention

[0004] The purpose of the present invention is to address the above problems in the prior art and to provide an internal support test head for a cylinder water pressure tester with better sealing effect and higher working efficiency.

[0005] The objectives of the present invention can be achieved through the following technical solutions: an internal support test head of a cylinder water pressure testing machine comprises a fixed plate, a support tube with an opening facing downward is fixedly connected to the lower side of the fixed plate, a cylindrical internal support shaft seat is coaxially fixedly connected to the lower end of the support tube, a water injection rod is coaxially provided to the support tube, a driving member capable of driving the water injection rod to reciprocate axially is provided on the fixed plate, an air passage is formed between the outer side of the water injection rod and the internal support shaft seat, and the invention is characterized in that a sealing gasket is positioned on the lower end face of the internal support shaft seat, the lower end of the water injection rod passes through the internal support shaft seat and the sealing gasket, a cylindrical internal support block is sleeved on the middle part of the water injection rod and the water injection rod can reciprocate relative to the internal support block, a conical surface is provided on the middle part of the water injection rod and the conical surface can push the lower end of the internal support block to open.

[0006] The cylinder water pressure tester is provided with a mobile driving mechanism that can drive the fixed plate to move back and forth. When working, the cylinder is placed on the conveying plate, and the mobile driving mechanism drives the fixed plate to descend, so that the sealing gasket is pressed against the edge of the threaded bottle mouth of the cylinder, and then the driving member drives the water injection rod to rise, and the conical surface on the water injection rod pushes the inner support block to open, so that the lower end outer wall of the inner support block is against and clamped on the inner end surface of the bottle mouth, and the inner support block drives the cylinder to move upward so that the bottle mouth end of the cylinder forms a seal with the sealing gasket. At this time, the mobile driving mechanism drives the fixed plate to move upward, so that the lower end of the cylinder is separated from the conveying plate and is in a suspended state. During the test, water is injected into the cylinder through the water injection rod, and the air in the cylinder is exhausted through the airway. After the cylinder is stable, the pressure test is performed on the cylinder through the pressure gauge. Then, compressed gas is sent into the cylinder through the airway, and the compressed gas pushes the water in the cylinder to be discharged through the water injection rod. By weighing the discharged water, the volume of the cylinder can be obtained. After the test, the mobile drive mechanism drives the fixed plate to move down and places the steel cylinder on the conveying plate, and drives the water injection rod to move down through the driving member. At this time, the conical surface is separated from the inner support block, and the lower end of the inner support block is reset. At this time, the mobile drive mechanism drives the fixed plate to rise and the water injection rod to rise and separate from the steel cylinder, completing the test of the steel cylinder. This internal support test head has the advantages of good sealing effect and high work efficiency. The mobile drive mechanism can use a cylinder or a motor to drive the fixed plate to reciprocate through the transmission of the screw and nut.

[0007] In the above-mentioned internal support test head of the cylinder water pressure tester, an internal support movable sleeve is provided in the internal support shaft seat, the water injection rod passes through the internal support movable sleeve, the lower end of the internal support movable sleeve is fixedly connected to the upper end of the internal support block, and a spring is provided between the upper end of the internal support movable sleeve and the internal support shaft seat, and the two ends of the spring respectively abut against the upper end of the internal support movable sleeve and the inner end surface of the support tube. When the internal support block and the internal support movable sleeve move upward, the conical surface of the water injection rod pushes the lower end of the internal support block and compresses the spring at the same time, and the spring plays a role of buffering and limiting. When the test is completed, when the driving member drives the water injection rod to move downward, the spring pushes the internal support movable sleeve and the internal support block to move downward, which is convenient for the elastic reset of the lower end of the internal support block, so that the work can proceed smoothly.

[0008] In the above-mentioned internal support test head of the cylinder water pressure tester, the outer sleeve of the water injection rod is provided with a limit sleeve, the limit sleeve is located in the support tube, the upper end of the limit sleeve can abut against the inner end surface of the support tube, and the lower end of the limit sleeve abuts against the upper end surface of the internal support movable sleeve. By setting the limit sleeve, the movement position of the internal support movable sleeve and the internal support block relative to the support tube is limited, and the conical surface is prevented from pushing the lower end of the internal support block to make the lower end of the internal support block excessively open, which has the advantages of reasonable and reliable operation.

[0009] In the above-mentioned internal support test head of the cylinder hydraulic tester, the lower end of the internal support block is provided with a plurality of elastic convex bodies, and the conical surface can push the elastic convex bodies to open. When the conical surface of the water injection rod is separated from the lower end of the internal support block, the elastic convex bodies are reset by elastic reset, so that the reset effect of the elastic convex bodies is achieved.

[0010] In the above-mentioned internal support test head of the cylinder water pressure tester, an elastic ring is sleeved on the outer side of the internal support block and the elastic ring can push the elastic protrusion to reset inward. When the conical surface of the water injection rod is separated from the lower end of the internal support block, the elastic protrusion is reset by the elastic reset of the elastic protrusion and the elastic ring drives the elastic protrusion to reset, so that the reset effect of the elastic protrusion is more ideal.

[0011] In the above-mentioned internal support test head of the cylinder water pressure tester, the driving member is a cylinder whose cylinder body is fixedly connected to the fixed plate, the lower end of the piston rod of the cylinder is fixedly connected to a connection block with a water channel, the upper end of the water injection rod is fixedly connected to the connection block and the water injection rod is connected to the connection block. The driving member is a cylinder, so that the translation speed of the water injection rod is faster and has the advantage of more reliable operation. By setting the above-mentioned connection block, it has the advantage of being easy to connect the water pipe.

[0012] In the above-mentioned internal support test head of the cylinder hydraulic tester, the upper end of the internal support movable sleeve is provided with a limiting convex shoulder 1, the inner side wall of the internal support shaft seat is provided with a limiting convex shoulder 2, and the limiting convex shoulder 1 can abut against the limiting convex shoulder 2. The limiting convex shoulder 1 can abut against the limiting convex shoulder 2, thereby preventing the internal support movable sleeve from falling off the internal support shaft seat.

[0013] In the above-mentioned internal support test head of the cylinder water pressure testing machine, a sealing ring is provided between the outer wall of the internal support movable sleeve and the inner wall of the internal support shaft seat, and an interface connected to the airway is provided on the outer side of the internal support shaft seat, and the interface is located on the lower side of the sealing ring.

[0014] In the above-mentioned internal support test head of the cylinder hydraulic tester, the internal support shaft seat and the fixing plate are fixedly connected through a plurality of connecting columns, and the connecting block is located between the plurality of connecting columns. The connecting block is located between the connecting columns, so that when the connecting block is connected with the external pipe, interference is avoided, and the structure is simple and easy to use.

[0015] In the above-mentioned internal support test head of the steel cylinder water pressure tester, the lower end of the water injection rod is provided with a telescopic tube, the upper end of the telescopic tube is inserted into the lower end of the water injection rod, and a seal is formed between the outer wall of the telescopic tube and the water injection rod. The water injection rod is provided with a telescopic tube, and when the driving member drives the water injection rod to lift, the conical surface on the water injection rod pushes the inner support block to open, so that the lower end outer wall of the inner support block abuts and is clamped on the inner end surface of the bottle mouth, the telescopic tube is in an extended state, so that the lower end of the telescopic tube can be close to the bottom surface of the steel cylinder. After the test is completed, when the driving member pushes the water injection rod downward, the telescopic tube retracts into the water injection rod, so that the water injection rod can move downward, making the test more accurate and the structure simpler.

[0016] In the internal support test head of the above-mentioned steel cylinder water pressure tester, a second spring is provided between the telescopic tube and the water injection rod, and the two ends of the second spring are respectively against between the water injection rod and the telescopic tube, and the second spring pushes the telescopic tube to move downward. The second spring pushes the telescopic tube to move downward, so that the telescopic tube is always extended from the water injection rod and against the inner bottom surface of the steel cylinder.

[0017] Compared with the prior art, the internal support test head of this cylinder water pressure tester has the following advantages:

[0018] 1. The driving member drives the water injection rod to move upward relative to the inner support block, so that the conical surface of the water injection rod can open the lower end of the inner support block, so that the inner support block is clamped with the inner port of the steel cylinder. The water injection rod drives the steel cylinder to move upward through the inner support block and forms a seal between the bottle mouth end of the steel cylinder and the sealing gasket, which has the advantages of good sealing effect and high working efficiency;

[0019] 2. By setting the limit sleeve, the moving position of the inner support movable sleeve and the inner support block relative to the support tube is limited, so as to avoid the conical surface pushing the lower end of the inner support block to cause the lower end of the inner support block to open excessively, which has the advantages of reasonable and reliable operation;

[0020] 3. The limiting boss 1 of the inner support movable sleeve can be abutted against the limiting boss 2 of the inner support shaft seat, thereby preventing the inner support movable sleeve from falling off the inner support shaft seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional schematic diagram of the internal support test head.

[0022] Figure 2 It is a cross-sectional schematic diagram of the internal support test head.

[0023] Figure 3 It is a working schematic diagram of the internal support test head.

[0024] In the figure, 1, fixed plate; 2, supporting cylinder; 3, water injection rod; 3a, conical surface; 4, driving member; 4a, cylinder; 5, airway; 6, sealing gasket; 7, inner support block; 7a, elastic convex body; 8, inner support movable sleeve; 8a, limiting shoulder 1; 9, inner support shaft seat; 9a, limiting shoulder 2; 10, spring; 11, limiting sleeve; 12, elastic ring; 13, sealing ring; 14, connecting column; 15, conveying plate; 16, movable driving mechanism; 17, connecting block; 18, telescopic tube; 19, spring 2. DETAILED DESCRIPTION

[0025] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0026] like Figures 1 to 3 As shown, the internal support test head of the cylinder water pressure test machine includes a fixed plate 1, a support tube 2 with an opening facing downward is fixedly connected to the lower side of the fixed plate 1, and the internal support shaft seat 9 is fixedly connected to the fixed plate 1 through four connecting columns 14. The lower end of the support tube 2 is coaxially fixedly connected to the cylindrical internal support shaft seat 9, and the support tube 2 is coaxially provided with a water injection rod 3. The fixed plate 1 is provided with a driving member 4 that can drive the water injection rod 3 to reciprocate axial translation. The driving member 4 is a cylinder 4a whose cylinder body is fixedly connected to the fixed plate 1, and the lower end of the piston rod of the cylinder 4a is fixedly connected to a connecting block 17 with a water channel. The upper end of the water injection rod 3 is fixedly connected to the connecting block 17 and the water injection hole of the water injection rod 3 is connected to the connecting block 17. The connecting block 17 is located between the four connecting columns 14, so that when the connecting block 17 is connected to the external pipeline, interference is avoided, and it has the advantages of simple structure and convenient use.

[0027] An air passage 5 is formed between the outer side of the water injection rod 3 and the inner support shaft seat 9. A sealing gasket 6 is positioned on the lower end surface of the inner support shaft seat 9. The lower end of the water injection rod 3 passes through the inner support shaft seat 9 and the sealing gasket 6. The middle part of the water injection rod 3 is sleeved with a cylindrical inner support block 7. The water injection rod 3 can reciprocate relative to the inner support block 7. A conical surface 3a is provided in the middle part of the water injection rod 3. A plurality of elastic protrusions 7a are provided at the lower end of the inner support block 7. The conical surface 3a can push the elastic protrusions 7a to open outward. An elastic ring 12 is sleeved on the outer side of the inner support block 7 and the elastic ring 12 can push the elastic protrusions 7a to reset inward.

[0028] An inner support sleeve 8 is provided inside the inner support shaft seat 9, and the water injection rod 3 passes through the inner support sleeve 8. The lower end of the inner support sleeve 8 is fixedly connected to the upper end of the inner support block 7. The upper end of the inner support sleeve 8 is provided with a limiting convex shoulder 1 8a, and the inner side wall of the inner support shaft seat 9 is provided with a limiting convex shoulder 2 9a. The limiting convex shoulder 1 8a can abut against the limiting convex shoulder 2 9a. A spring 10 is provided between the upper end of the inner support sleeve 8 and the inner support shaft seat 9, and the two ends of the spring 10 abut against the upper end of the inner support sleeve 8 and the inner end surface of the support tube 2 respectively. The outer side of the water injection rod 3 is provided with a limit sleeve 11, and the limit sleeve 11 is located in the support tube 2. The upper end of the limit sleeve 11 can abut against the inner end surface of the support tube 2, and the lower end of the limit sleeve 11 abuts against the upper end surface of the inner support movable sleeve 8, which limits the moving distance of the inner support movable sleeve 8 and the inner support block 7 relative to the support tube 2, and prevents the conical surface 3a from pushing the lower end of the inner support block 7 to cause the lower end of the inner support block 7 to open excessively, which has the advantages of reasonable and reliable operation.

[0029] A sealing ring 13 is provided between the outer wall of the inner support movable sleeve 8 and the inner wall of the inner support shaft seat 9 . An interface communicating with the airway 5 is provided on the outer side of the inner support shaft seat 9 , and the interface is located at the lower side of the sealing ring 13 .

[0030] A telescopic tube 18 is provided at the lower end of the water injection rod 3, and the upper end of the telescopic tube 18 is inserted into the lower end of the water injection rod 3, and a seal is formed between the outer wall of the telescopic tube 18 and the water injection rod 3. A second spring 19 is provided between the telescopic tube 18 and the water injection rod 3, and the two ends of the second spring 19 are respectively against between the water injection rod 3 and the telescopic tube 18, and the second spring 19 pushes the telescopic tube 18 to translate downward.

[0031] The cylinder water pressure testing machine is provided with a moving driving mechanism 16 which can drive the fixed plate 1 to move back and forth. During operation, the cylinder is placed on the conveying plate 15, and the moving driving mechanism 16 drives the fixed plate 1 to move down, so that the water injection rod 3 and the inner support block 7 extend into the cylinder, and the sealing gasket 6 is pressed against the edge of the threaded bottle mouth of the cylinder, and then the cylinder 4a drives the water injection rod 3 to rise, and the conical surface 3a on the water injection rod 3 pushes the elastic convex body 7a of the inner support block 7 to open, so that the outer side wall of the elastic convex body 7a abuts against and is clamped on the inner end surface of the bottle mouth, and the inner support block 7 drives the cylinder to move upward so that the bottle mouth end of the cylinder forms a seal with the sealing gasket 6. At this time, the spring 2 19 pushes the telescopic tube 18 so that the lower end of the telescopic tube 18 is close to the inner bottom surface of the cylinder. At this time, the moving driving mechanism 16 drives the fixed plate 1 to move upward, so that the lower end of the cylinder is separated from the conveying plate 15 and is in a suspended state, and then the cylinder is tested. During the test, water is injected into the steel cylinder through the water injection rod 3, and the air in the steel cylinder is exhausted through the airway 5. After the steel cylinder is filled with water and stabilized, the pressure in the steel cylinder is tested through the pressure gauge; then compressed gas is sent into the steel cylinder through the airway 5, and the compressed gas pushes the water in the steel cylinder to be discharged through the water injection rod 3. By weighing the discharged water, the volume of the steel cylinder can be obtained. After the test, the mobile drive mechanism 16 drives the fixed plate 1 to move down and place the steel cylinder on the conveying plate 15, and drives the water injection rod 3 to move down through the cylinder 4a, and at the same time makes the telescopic tube 18 retract against the elastic force of the spring 2 19. At this time, the conical surface 3a is separated from the inner support block 7, and the elastic convex body 7a is reset by the elastic reset and the elastic ring 12 drives the elastic convex body 7a to reset. The fixed plate 1 is driven to rise by the mobile drive mechanism 16, and the water injection rod 3 and the inner support block 7 are raised and separated from the steel cylinder, completing the test of the steel cylinder. This inner support type test head has the advantages of good sealing effect and high working efficiency. The moving driving mechanism 16 can use a cylinder 4a or a motor to drive the fixing plate 1 to move up and down through the transmission of a screw rod and a screw nut.

[0032] When the inner support block 7 and the inner support movable sleeve 8 move upward, the conical surface 3a of the water injection rod 3 pushes the lower end of the inner support block 7 and compresses the spring 10. The spring 10 plays a role of buffering and limiting. After the test, when the driving member 4 drives the water injection rod 3 to move downward, the spring 10 pushes the inner support movable sleeve 8 and the inner support block 7 to move downward, which is convenient for the elastic reset of the lower end of the inner support block 7, so that the work can proceed smoothly.

[0033] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0034] Although the present invention uses more terms such as fixed plate 1, support tube 2, water injection rod 3, conical surface 3a, driving member 4, cylinder 4a, airway 5, sealing pad 6, inner support block 7, elastic convex body 7a, inner support movable sleeve 8, limiting shoulder 1 8a, inner support shaft seat 9, limiting shoulder 2 9a, spring 10, limiting sleeve 11, elastic ring 12, sealing ring 13, connecting column 14, conveying plate 15, mobile driving mechanism 16, connecting block 17, telescopic tube 18, spring 2 19, etc., it does not exclude the possibility of using other terms. The use of these terms is only for more convenient description and explanation of the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. An internal support test head of a cylinder water pressure tester, comprising a fixed plate (1), a support tube (2) with an opening facing downwards is fixedly connected to the lower side of the fixed plate (1), a cylindrical internal support shaft seat (9) is coaxially fixedly connected to the lower end of the support tube (2), a water injection rod (3) is coaxially provided on the support tube (2), a driving member (4) capable of driving the water injection rod (3) to reciprocate axial translation is provided on the fixed plate (1), an air passage (5) is formed between the outer side of the water injection rod (3) and the internal support shaft seat (9), characterized in that: A sealing gasket (6) is positioned on the lower end surface of the inner support shaft seat (9), the lower end of the water injection rod (3) passes through the inner support shaft seat (9) and the sealing gasket (6), the middle part of the water injection rod (3) is sleeved with a cylindrical inner support block (7), and the water injection rod (3) can reciprocate relative to the inner support block (7), and the middle part of the water injection rod (3) is provided with a conical surface (3a), and the conical surface (3a) can push the lower end of the inner support block (7) to open.

2. The internal support test head of the cylinder water pressure tester according to claim 1, characterized in that: The inner support shaft seat (9) is provided with an inner support movable sleeve (8), the water injection rod (3) passes through the inner support movable sleeve (8), the lower end of the inner support movable sleeve (8) is fixedly connected to the upper end of the inner support block (7), and a spring (10) is provided between the upper end of the inner support movable sleeve (8) and the inner support shaft seat (9), and the two ends of the spring (10) respectively abut against the upper end of the inner support movable sleeve (8) and the inner end surface of the support tube (2).

3. The internal support test head of the cylinder water pressure tester according to claim 2, characterized in that: The outer side of the water injection rod (3) is provided with a limiting sleeve (11), and the limiting sleeve (11) is located in the supporting tube (2). The upper end of the limiting sleeve (11) can abut against the inner end surface of the supporting tube (2), and the lower end of the limiting sleeve (11) abuts against the upper end surface of the inner supporting movable sleeve (8).

4. The internal support test head of the cylinder water pressure tester according to claim 1, 2 or 3, characterized in that: The lower end of the inner support block (7) is provided with a plurality of elastic protrusions (7a), and the conical surface (3a) can push the elastic protrusions (7a) to open.

5. The internal support test head of the cylinder water pressure tester according to claim 4, characterized in that: An elastic ring (12) is sleeved on the outer side of the inner support block (7), and the elastic ring (12) can push the elastic protrusion (7a) to return to the inside.

6. The internal support test head of the cylinder water pressure tester according to claim 1, 2 or 3, characterized in that: The driving member (4) is a cylinder (4a) whose cylinder body is fixedly connected to the fixed plate (1); the lower end of the piston rod of the cylinder (4a) is fixedly connected to a connecting block (17) having a water channel; the upper end of the water injection rod (3) is fixedly connected to the connecting block (17) and the water injection rod (3) is in communication with the connecting block (17).

7. The internal support test head of the cylinder water pressure tester according to claim 2 or 3, characterized in that: The upper end of the inner support movable sleeve (8) is provided with a limiting shoulder 1 (8a), the inner side wall of the inner support shaft seat (9) is provided with a limiting shoulder 2 (9a), and the limiting shoulder 1 (8a) can abut against the limiting shoulder 2 (9a).

8. The internal support test head of the cylinder water pressure tester according to claim 7, characterized in that: A sealing ring (13) is provided between the outer wall of the inner support movable sleeve (8) and the inner wall of the inner support shaft seat (9), and an interface connected to the airway (5) is provided on the outer side of the inner support shaft seat (9), and the interface is located on the lower side of the sealing ring (13).

9. The internal support test head of the cylinder hydraulic tester according to claim 6, characterized in that: The inner support shaft seat (9) and the fixed plate (1) are fixedly connected via a plurality of connecting columns (14), and the connecting block (17) is located between the plurality of connecting columns (14).

10. The internal support test head of the cylinder water pressure tester according to claim 1, 2 or 3, characterized in that: A telescopic tube (18) is provided at the lower end of the water injection rod (3), the upper end of the telescopic tube (18) is inserted into the lower end of the water injection rod (3), a seal is formed between the outer wall of the telescopic tube (18) and the water injection rod (3), a second spring (19) is provided between the telescopic tube (18) and the water injection rod (3), the two ends of the second spring (19) respectively abut between the water injection rod (3) and the telescopic tube (18), and the second spring (19) pushes the telescopic tube (18) to move downward.

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