Steel pipe necking process for air conditioner silencer

Abstract

The present invention relates to the technical field of steel pipe necking, and particularly to the steel pipe necking process of an air conditioner silencer, which comprises the following steps: S1, measure the required necking distance at both ends and make marks; S2, heat the marked necking section and perform uniform forging on this position to form a pre-necking; S3, sleeved an adapted prefabricated necking die at the pre-necking for extrusion and rotation; S4, stop extrusion, perform accelerated rotation, and wait for the necking section to cool; S5, remove the prefabricated necking die from the necking section and perform heat treatment; S6, cut off the pre-necking at both sides of the necking section through a cutting machine, and polish the necking section through a polishing device; S7, perform silencing test. In the present invention, by heating the marked necking section of the silencer steel pipe and sleeving an adapted prefabricated necking die at the pre-necking for extrusion and rotation, the silencer steel pipe after necking can be obtained quickly and stably. At the same time, the silencer steel pipe after necking has a good silencing function.

Description

Technical Field

[0001] The present invention relates to the technical field of steel pipe necking, and particularly to the steel pipe necking process for air conditioner silencers. Background Art

[0002] The steel pipe of the air conditioner internal silencer needs to be necked for easy connection. The necking of the silencer pipe is a forming process in which a pre-formed silencer pipe is reduced in diameter at its mouth by a necking machine. In the prior art, when necking the silencer pipe, the necking section is prone to tangential instability and wrinkling due to the action of a large tangential compressive stress, and the simple wall area that plays a force transmission role is prone to axial instability and wrinkling due to the action of an axial compressive stress, so it is difficult to obtain a stable and effective steel pipe for air conditioner silencers.

[0003] Therefore, we propose a steel pipe necking process for air conditioner silencers to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a steel pipe necking process for air conditioner silencers to solve the deficiencies existing in the prior art.

[0005] The steel pipe necking process for air conditioner silencers includes the following steps:

[0006] S1. Clean the prefabricated steel pipe of the silencer, wash the oil stain on the steel pipe of the silencer, measure the required necking distance at both ends, mark it with a laser marking machine, and the marking position is 6 - 8 cm away from the pipe mouth;

[0007] S2. Heat the marked necking sections at both ends of the steel pipe of the silencer to 850 - 950 °C, and at a position 1 - 2 cm away from the port of the steel pipe of the silencer, evenly forge this position with a small forging press, so that both ends of the port tilt and contract inward to form a pre-necking;

[0008] S3. Continue to heat the marked necking sections at both ends of the steel pipe of the silencer to 1080 - 1120 °C, sleeved an adapted prefabricated necking die at the pre-necking for extrusion and rotation, the rotation speed is 1.2 - 1.4 r / min, and the extrusion pressure is 2.2 - 2.8 MPa;

[0009] S4. When the prefabricated necking die moves to the marked position, stop extrusion, accelerate rotation, the rotation speed is 3 - 6 r / min, the rotation time is 6 - 8 min, and then let it stand still until the necking section cools;

[0010] S5. When the necking section cools to room temperature, the prefabricated necking die is withdrawn from the necking section, the necking at both ends of the steel pipe of the silencer is formed, and it is placed in a vacuum heat treatment furnace for heat treatment, and the heat treatment time is 8 - 10 h;

[0011] S6. During heat treatment and cooling to room temperature, the pre-necked parts at both sides of the necking section are cut off by a cutting machine to make the cut surface smooth, and the necking section is polished by a polishing device to make the inner and outer surfaces of the necking section smooth and bright;

[0012] S7. Perform a sound insulation test on the muffler steel pipe after necking. After passing the test, apply oil and store it.

[0013] Preferably, in S1, the muffler steel pipe rotates evenly for 1 circle under the laser marking machine to make a mark.

[0014] Preferably, in S2, when forging by a small forging press, the forging block is inclined, and the inclination angle is 45 - 60°.

[0015] Preferably, in S3, when the prefabricated necking die is extruded and rotated, the temperature of the marked necking section is maintained, and it is carried out under argon protection.

[0016] Preferably, in S6, when cutting off the pre-necking, the cutting distance is (1.1 ± 0.2) - (2.1 ± 0.2) cm.

[0017] Preferably, in S6, during polishing, the outer wall of the necking section, the connection between the necking section and the muffler steel pipe, and the port surface are polished, and at the same time, the inner wall of the necking section is polished by extending from the port into the necking section.

[0018] Preferably, in S7, during the sound insulation test, install the air conditioner sound insulation pipe on the test rack, and use an air flow with a wind volume of 200 - 300 m 3 / s and a wind speed of 0.6 - 0.8 m / s to pass through the air conditioner sound insulation pipe, and measure the decibels.

[0019] The beneficial effects of the present invention are:

[0020] In the present invention, by heating the marked necking section of the muffler steel pipe and sleeving the adapted prefabricated necking die at the pre-necking part for extrusion and rotation, the muffler steel pipe after necking can be obtained quickly and stably. At the same time, the muffler steel pipe after necking has a good sound insulation function. Specific Embodiments

[0021] The following further explains the present invention with specific embodiments.

[0022] Embodiment 1

[0023] The necking process of the air conditioner muffler steel pipe includes the following steps:

[0024] S1. Clean the prefabricated silencer steel pipe, wash off the oil stain on the silencer steel pipe, measure the required necking distance at both ends, and make marks through a laser marking machine. The silencer steel pipe rotates evenly under the laser marking machine for 1 circle to make marks, and the marking position is 6 cm away from the pipe orifice;

[0025] S2. Heat the marked necking sections at both ends of the silencer steel pipe to 850 °C. At a position 1.2 cm away from the port of the silencer steel pipe, use a small forging press to evenly forge this position, so that both ports incline and contract inward to form a pre-necking;

[0026] S3. Continue to heat the marked necking sections at both ends of the silencer steel pipe to 1080 °C, sleeve the adapted prefabricated necking mold on the pre-necking for extrusion rotation, the rotation speed is 1.2 r / min, and the extrusion pressure is 2.2 MPa;

[0027] S4. When the prefabricated necking mold moves to the marked position, stop extrusion, perform accelerated rotation, the rotation speed is 3 r / min, the rotation time is 6 min, and then let it stand still until the necking section cools;

[0028] S5. When the necking section cools to room temperature, the prefabricated necking mold is withdrawn from the necking section, the necking at both ends of the silencer steel pipe is formed, and it is placed in a vacuum heat treatment furnace for heat treatment, and the heat treatment time is 8 h;

[0029] S6. When it cools to room temperature during heat treatment, cut off the pre-necking at both sides of the necking section through a cutting machine, the cutting distance is 1.2 cm, so that the cut is flat, and polish the necking section through a polishing device, so that the inner and outer surfaces of the necking section are smooth;

[0030] S7. Conduct a sound insulation test on the silencer steel pipe after necking. After passing the test, apply oil and store it.

[0031] Further, in S2, when forging through a small forging press, the forging block is inclined, and the inclination angle is 45°.

[0032] Further, in S3, when the prefabricated necking mold is extruded and rotated, keep the temperature of the marked necking section, and at the same time carry out under argon protection.

[0033] Further, in S6, when polishing, polish the outer wall of the necking section, the connection between the necking section and the silencer steel pipe, and the port surface, and at the same time polish the inner wall of the necking section by extending from the port into the necking section.

[0034] Further, in S7, during the sound insulation test, install the air-conditioning sound insulation pipe on the test rack, and use an air flow with a wind volume of 200 m 3 / s and a wind speed of 0.6 m / s to pass through the air-conditioning sound insulation pipe and measure the decibels.

[0035] Example 2

[0036] The necking process of the air conditioner silencer steel pipe includes the following steps:

[0037] S1. Clean the prefabricated silencer steel pipe, wash the oil stain on the silencer steel pipe, measure the required necking distance at both ends, and make marks through a laser marking machine. The silencer steel pipe rotates evenly under the laser marking machine for 1 circle to make marks, and the marking position is 7 cm away from the pipe orifice;

[0038] S2. Heat the marked necking sections at both ends of the silencer steel pipe to 900 °C. At a position 1.8 cm away from the port of the silencer steel pipe, use a small forging press to evenly forge this position, so that both ports tilt and contract inward to form a pre-necking;

[0039] S3. Continue to heat the marked necking sections at both ends of the silencer steel pipe to 1080 - 1120 °C, sleeved the adapted prefabricated necking die at the pre-necking for extrusion rotation, the rotation speed is 1.3 r / min, and the extrusion pressure is 2.6 MPa;

[0040] S4. When the prefabricated necking die moves to the marked position, stop extrusion, perform accelerated rotation, the rotation speed is 4 r / min, the rotation time is 7 min, and then let it stand still until the necking section cools;

[0041] S5. When the necking section cools to room temperature, the prefabricated necking die is withdrawn from the necking section, the necking at both ends of the silencer steel pipe is formed, and it is placed in a vacuum heat treatment furnace for heat treatment, and the heat treatment time is 9 h;

[0042] S6. When the heat treatment cools to room temperature, the pre-necking at both sides of the necking section is cut off by a cutting machine, the cutting distance is 1.8, so that the cut is flat, and the necking section is polished by a polishing device, so that the inner and outer surfaces of the necking section are smooth;

[0043] S7. Conduct a sound insulation test on the silencer steel pipe after necking is completed. After passing the test, apply oil and store it.

[0044] Furthermore, in S2, when forging by a small forging press, the forging block is inclined, and the inclination angle is 55°.

[0045] Furthermore, in S3, when the prefabricated necking die is extruded and rotated, keep the temperature of the marked necking section and conduct it under argon protection.

[0046] Furthermore, in S6, when polishing, polish the outer wall of the necking section, the connection between the necking section and the silencer steel pipe, and the port surface, and at the same time extend from the port into the necking section to polish the inner wall of the necking section.

[0047] Further, in S7, during the silencing test, install the air conditioner silencing pipe on the test stand, and use an air flow with a volume of 250 m 3 / s and a wind speed of 0.7 m / s to pass through the air conditioner silencing pipe, and measure the decibels.

[0048] Example 3

[0049] The process of necking down the steel pipe of the air conditioner silencer includes the following steps:

[0050] S1. Clean the prefabricated silencer steel pipe, wash the oil stain on the silencer steel pipe, and measure the required necking-down distance at both ends, and mark it with a laser marking machine. The silencer steel pipe rotates evenly under the laser marking machine for 1 circle to make a mark, and the marking position is 8 cm away from the pipe orifice;

[0051] S2. Heat the marked necking-down sections at both ends of the silencer steel pipe to 950 °C, and at a position 2 cm away from the port of the silencer steel pipe, use a small forging press to evenly forge this position, so that the two ports tilt and contract inward to form a pre-necking;

[0052] S3. Continue to heat the marked necking-down sections at both ends of the silencer steel pipe to 1120 °C, and sleeved the adapted prefabricated necking die on the pre-necking for extrusion and rotation, with a rotation speed of 1.4 r / min and an extrusion pressure of 2.8 MPa;

[0053] S4. When the prefabricated necking die moves to the marked position, stop extrusion, perform accelerated rotation, with a rotation speed of 6 r / min and a rotation time of 8 min, and then let it stand still until the necking-down section cools;

[0054] S5. When the necking-down section cools to room temperature, the prefabricated necking die is withdrawn from the necking-down section, and the necking-downs at both ends of the silencer steel pipe are formed and placed in a vacuum heat treatment furnace for heat treatment, and the heat treatment time is 10 h;

[0055] S6. During the heat treatment cooling to room temperature, cut off the pre-necking at both sides of the necking-down section with a cutting machine, and the cutting distance is 2 cm to make the cut surface flat, and polish the necking-down section with a polishing device to make the inner and outer surfaces of the necking-down section smooth;

[0056] S7. Conduct a silencing test on the silencer steel pipe after necking-down is completed, and store it after oiling if it passes the test.

[0057] Further, in S2, when forging with a small forging press, the forging block is inclined, and the inclination angle is 60°.

[0058] Further, in S3, when the prefabricated necking die is extruded and rotated, maintain the temperature of the marked necking-down section and perform it under argon protection.

[0059] Further, in S6, during polishing, the outer wall of the necking section, the connection between the necking section and the silencer steel pipe, and the port surface are polished. At the same time, the inner wall of the necking section is polished by extending from the port into the necking section.

[0060] Further, in S7, during the silencing test, the air-conditioning silencing pipe is installed on the test rack, and an air flow with a volume of 300 m 3 / s and a wind speed of 0.8 m / s passes through the air-conditioning silencing pipe to measure the decibels.

[0061] The silencing test is carried out on the air-conditioning silencing pipes after necking in Examples 1-3. The air-conditioning silencing pipes are installed on the test rack, and an air flow with a volume of 200-300 m3 / s and a wind speed of 0.6-0.8 m / s passes through the air-conditioning silencing pipes to measure the decibels, as shown in the following table:

[0062] Embodiment <![CDATA[Air volume m 3 / s]]> Wind speed m / s Decibel dB 1 200 0.6 20 2 250 0.7 22 3 300 0.8 25

[0063] According to Examples 1-3, it can be seen that the silencer steel pipe after necking has a good silencing function.

[0064] In the present invention, by heating the marked necking section of the silencer steel pipe and sleeving the adapted prefabricated necking die on the pre-necking position for extrusion rotation, the silencer steel pipe after necking can be obtained quickly and stably. At the same time, the silencer steel pipe after necking has a good silencing function.

[0065] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. The steel pipe necking process of the air conditioner silencer is characterized in that It includes the following steps: S1. Clean the prefabricated silencer steel pipe, wash the oil stain on the silencer steel pipe, measure the required necking distance at both ends, mark it with a laser marking machine, and the marking position is 6-8 cm away from the pipe orifice; S2. Heat the marked necking sections at both ends of the silencer steel pipe to 850-950 °C, and at a position 1-2 cm away from the port of the silencer steel pipe, evenly forge this position with a small forging press, so that the two ports tilt and contract inward to form a pre-necking; S3. Continue to heat the marked necking sections at both ends of the silencer steel pipe to 1080-1120 °C, sleeved the adapted prefabricated necking die on the pre-necking for extrusion rotation, the rotation speed is 1.2-1.4 r / min, and the extrusion pressure is 2.2-2.8 MPa; S4. When the prefabricated necking die moves to the marked position, stop extrusion, perform accelerated rotation, the rotation speed is 3-6 r / min, the rotation time is 6-8 min, and then let it stand still until the necking section cools; S5. When the necking section cools to room temperature, the prefabricated necking die is withdrawn from the necking section, the necking at both ends of the silencer steel pipe is formed, and it is placed in a vacuum heat treatment furnace for heat treatment, and the heat treatment time is 8-10 h; S6. When cooling to room temperature after heat treatment, cut off the pre-necking at both sides of the necking section with a cutting machine to make the cut surface flat, and polish the necking section with a polishing device to make the inner and outer surfaces of the necking section smooth; S7. Conduct a silencing test on the silencer steel pipe after necking is completed, and store it after oiling when the test is qualified.

2. The steel pipe necking process of the air conditioner silencer according to claim 1, characterized in that, In the above S1, the silencer steel pipe rotates evenly for 1 circle under the laser marking machine to make a mark.

3. The steel pipe necking process of the air conditioner silencer according to claim 1, wherein In the above S2, when forging with a small forging press, the forging block is inclined, and the inclination angle is 45-60°.

4. The steel pipe necking process of the air conditioner silencer according to claim 1, characterized in that In the above S3, when performing extrusion rotation with the prefabricated necking die, keep the temperature of the marked necking section and conduct it under argon protection.

5. The steel pipe necking process of the air conditioner silencer according to claim 1, characterized in that, In the above S6, when cutting off the pre-necking, the cutting distance is (1.1±0.2)-(2.1±0.2) cm.

6. The steel pipe necking process of the air conditioner silencer according to claim 1, characterized in that In the above S6, when polishing, polish the outer wall of the necking section, the connection between the necking section and the silencer steel pipe, and the port surface, and at the same time extend from the port into the necking section to polish the inner wall of the necking section.

7. The steel pipe necking process for an air conditioner silencer according to claim 1, characterized in that , in the S7, during the sound attenuation test, install the air conditioner sound attenuation pipe on the test stand, and let an air flow with a volume of 200 - 300 m 3 / s and a wind speed of 0.6 - 0.8 m / s pass through the air conditioner sound attenuation pipe to measure the decibels.