阅读说明：本技术 一种高强度氮气弹簧生产工艺及方法 (Production process and method of high-strength nitrogen spring ) 是由 沈飞 阚星辉 于 2020-06-16 设计创作，主要内容包括：本发明公开了一种高强度氮气弹簧生产工艺及方法,包括以下操作步骤：S1：锻造,以380-400℃温度预热,之后以5-8℃/min的速度将温度升高至850-880℃,保温20-30分钟,之后以3-5℃/min的速度将温度升高至1150-1200℃,保温1-2小时；S2：压铸,将加热后的缸体胚件使用压力机进行压铸,使得缸体胚件的径向压铸形变量为20-25%；S3：裁切、打磨,将缸体胚件进行切割、打磨,得到圆钢体,备用；S4：车加工；S5：装配；S6：质检。本发明通过对缸体胚件进行高温高压锻造处理,在氮气的保护下防止缸体胚件出线过氧化现象,能够在缸体结构内形成均匀的马氏体、奥氏体结晶,有效改善缸体胚件的结构强度,提高缸体的耐高压性能,防止缸体爆裂,提高氮气弹簧的支撑强度。(The invention discloses a production process and a method of a high-strength nitrogen spring, which comprises the following operation steps: s1: forging, preheating at the temperature of 380-400 ℃, raising the temperature to 850-880 ℃ at the speed of 5-8 ℃/min, preserving the heat for 20-30 minutes, raising the temperature to 1150-1200 ℃ at the speed of 3-5 ℃/min, and preserving the heat for 1-2 hours; s2: die-casting, namely die-casting the heated cylinder body blank by using a press machine to ensure that the radial die-casting deformation amount of the cylinder body blank is 20-25%; s3: cutting and polishing, namely cutting and polishing the cylinder body blank to obtain a round steel body for later use; s4: turning; s5: assembling; s6: and (6) quality inspection. According to the invention, through carrying out high-temperature high-pressure forging treatment on the cylinder body blank, the phenomenon of over oxidation of the outgoing line of the cylinder body blank is prevented under the protection of nitrogen, uniform martensite and austenite crystals can be formed in the cylinder body structure, the structural strength of the cylinder body blank is effectively improved, the high-pressure resistance of the cylinder body is improved, the cylinder body is prevented from bursting, and the supporting strength of the nitrogen spring is improved.)

1. A production process and a method of a high-strength nitrogen spring are characterized in that: the method comprises the following operation steps:

s1: forging, namely placing the cylinder body blank in a forging furnace, preheating at the temperature of 380-400 ℃, then increasing the temperature to 850-880 ℃ at the speed of 5-8 ℃/min, preserving heat for 20-30 minutes, then increasing the temperature to 1150-1200 ℃ at the speed of 3-5 ℃/min, preserving heat for 1-2 hours, and till the internal temperature of the cylinder body blank is completely consistent;

s2: die-casting, namely die-casting the heated cylinder body blank by using a press machine to ensure that the radial die-casting deformation amount of the cylinder body blank is 20-25%;

s3: cutting and polishing, namely cutting and polishing the cylinder body blank to obtain a round steel body for later use;

s4: turning, namely fixing the round steel body on a boring machine for boring, machining an inner cavity, machining the surface of the round steel body by using a lathe, and polishing the inner surface and the outer surface of the round steel body after machining is finished to obtain the gas spring cylinder body;

s5: assembling, namely respectively installing a cylinder body end cover, a cylinder body base, a piston rod and a sealing ring into a cylinder body, and then filling nitrogen into the cylinder body;

s6: and (4) performing quality inspection, namely after nitrogen is filled, putting the product into a detection box and immersing the product into water, and observing whether bubbles are generated for a period of time, wherein if no bubbles are generated, the product is qualified.

2. The production process and method of the high-strength nitrogen spring according to claim 1, wherein: in step S1, the forging furnace is nitrogen-gas atmosphere.

3. The production process and method of the high-strength nitrogen spring according to claim 1, wherein: and in the step S2, die casting is carried out for a plurality of times, the time of each die casting treatment is 40-60S, then the cylinder body blank is placed in a forging furnace to be heated, and the die casting is carried out repeatedly until the deformation requirement is met.

4. The production process and method of the high-strength nitrogen spring according to claim 1, wherein: and step S3, detecting whether the round steel body is qualified or not by using an eddy current flaw detector.

5. The production process and method of the high-strength nitrogen spring according to claim 1, wherein: in step S5, the pressure of nitrogen gas is 8-10 Mpa.

6. The production process and method of the high-strength nitrogen spring according to claim 1, wherein: in step S5, the piston rod is pretreated by PVD treatment technology, and a 10-20um TiC coating is formed on the surface of the piston rod.

Technical Field

The invention belongs to the technical field of nitrogen springs, and particularly relates to a production process and a production method of a high-strength nitrogen spring.

Background

The nitrogen spring is a part capable of realizing functions of supporting, buffering, braking, height and angle adjustment and the like, and is mainly applied to parts such as a cover cap, a door and the like in engineering machinery. The gas spring mainly comprises a piston rod, a piston, a sealing guide sleeve, a filler, a pressure cylinder, a joint and the like, wherein the pressure cylinder is a closed cavity, inert gas or oil-gas mixture is filled in the pressure cylinder, and the pressure in the cavity is several times or dozens of times of the atmospheric pressure. A reaction force is also created to the cylinder due to the need to maintain a high pressure inside the cylinder. At present, the cylinder body of the nitrogen spring is usually directly processed by stainless steel, and along with the influence of the thickness reduction of the cylinder body or the increase of the internal pressure intensity of the cylinder body, the cylinder body is under high pressure for a long time and can cause invisible deformation to the cylinder body, so that the air tightness of the cylinder body is influenced, and the service life of the nitrogen spring is shortened. Therefore, there is a need for a process and method for producing a high strength nitrogen spring that reduces the deformation caused by high pressure.

Disclosure of Invention

The invention aims to provide a production process and a method of a high-strength nitrogen spring, which aim to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a production process and a method of a high-strength nitrogen spring comprise the following operation steps:

s1: forging, namely placing the cylinder body blank in a forging furnace, preheating at the temperature of 380-400 ℃, then increasing the temperature to 850-880 ℃ at the speed of 5-8 ℃/min, preserving heat for 20-30 minutes, then increasing the temperature to 1150-1200 ℃ at the speed of 3-5 ℃/min, preserving heat for 1-2 hours, and till the internal temperature of the cylinder body blank is completely consistent;

s2: die-casting, namely die-casting the heated cylinder body blank by using a press machine to ensure that the radial die-casting deformation amount of the cylinder body blank is 20-25%;

s3: cutting and polishing, namely cutting and polishing the cylinder body blank to obtain a round steel body for later use;

s4: turning, namely fixing the round steel body on a boring machine for boring, machining an inner cavity, machining the surface of the round steel body by using a lathe, and polishing the inner surface and the outer surface of the round steel body after machining is finished to obtain the gas spring cylinder body;

s5: assembling, namely respectively installing a cylinder body end cover, a cylinder body base, a piston rod and a sealing ring into a cylinder body, and then filling nitrogen into the cylinder body;

s6: and (4) performing quality inspection, namely after nitrogen is filled, putting the product into a detection box and immersing the product into water, and observing whether bubbles are generated for a period of time, wherein if no bubbles are generated, the product is qualified.

Preferably, the forging furnace is nitrogen atmosphere in step S1.

Preferably, the die casting in step S2 is performed several times, each time the die casting process lasts for 40-60S, and then the cylinder blank is placed in a forging furnace to be heated, and the die casting is repeated until the deformation requirement is met.

Preferably, in step S3, the steel round body is tested for acceptability using an eddy current flaw detector.

Preferably, the nitrogen gas charging pressure in step S5 is 8-10 MPa.

Preferably, in step S5, the piston rod is pretreated by PVD technique, and a TiC coating of 10-20um is formed on the surface of the piston rod.

The invention has the technical effects and advantages that:

according to the invention, through carrying out high-temperature high-pressure forging treatment on the cylinder body blank, the phenomenon of over oxidation of the outgoing line of the cylinder body blank is prevented under the protection of nitrogen, uniform martensite and austenite crystals can be formed in the cylinder body structure, the structural strength of the cylinder body blank is effectively improved, the high-pressure resistance of the cylinder body is improved, the cylinder body is prevented from bursting, and the supporting strength of the nitrogen spring is improved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.