CN216912320U

CN216912320U - Pull rod mechanism

Info

Publication number: CN216912320U
Application number: CN202220649197.1U
Authority: CN
Inventors: 高利飞; 崔立英; 梅瑞雪
Original assignee: BEIJING JINGDIAO PRECISION MACHINERY MANUFACTURING CO LTD
Current assignee: BEIJING JINGDIAO PRECISION MACHINERY MANUFACTURING CO LTD
Priority date: 2022-03-24
Filing date: 2022-03-24
Publication date: 2022-07-08
Anticipated expiration: 2032-03-24

Abstract

The utility model relates to a pull rod mechanism, which comprises a pull rod and a mandrel, wherein the mandrel is of a hollow structure, and the pull rod is arranged in a central hole of the mandrel; an annular air cavity is formed on the inner wall of the pull rod and the mandrel, and compressed nitrogen is filled in the annular air cavity. The utility model has the advantages of simple structure, convenient manufacture, low cost, stable broach force and stable operation.

Description

Pull rod mechanism

Technical Field

The utility model belongs to the technical field of electric spindles of machine tools, and particularly relates to a pull rod mechanism.

Background

At present, elastic elements such as disc springs and spiral springs are generally used for providing axial tension for a pull rod mechanism in an electric spindle of a machine tool, but the elastic force of the elastic elements is attenuated along with the increase of broaching times under the influence of the characteristics of the elastic elements, so that the problems of reduction of the broaching force of the spindle and the like are caused. And if the adopted disc springs are about hundreds of disc springs, the consistency is difficult to keep due to long assembly time, the disc springs slide and deviate in the compression and reset processes, and the problems of vibration and the like are caused in the process of following the high-speed rotation of the main shaft rotor, so that the performance of the whole machine is changed, and the product processing effect is finally influenced. Although the adoption of the double-wire spiral spring can slow down the attenuation speed of the elastic force to a certain extent, the use cost is high.

Disclosure of Invention

The utility model aims to overcome the defects of the prior art and provides the pull rod mechanism which is simple in structure, convenient to manufacture, low in cost, stable in broach force and stable in operation.

In order to solve the technical problems, the utility model is realized by the following technical scheme: a pull rod mechanism comprises a pull rod and a mandrel, wherein the mandrel is of a hollow structure, and the pull rod is arranged in a central hole of the mandrel; an annular air cavity is formed on the inner wall of the pull rod and the mandrel, and compressed nitrogen is filled in the annular air cavity.

In the pull rod mechanism, the pull rod is of a stepped shaft structure and comprises a large-diameter end and a small-diameter end, the large-diameter end is attached to the inner wall of the mandrel, the small-diameter end is sleeved with the inner nest, the inner wall of the inner nest is attached to the small-diameter end of the pull rod, and the outer wall of the inner nest is attached to the inner wall of the mandrel; the annular air cavity is composed of an inner end face of an inner nested sleeve, an inner end face of a large-diameter end, an outer wall of a small-diameter end and an inner wall of the mandrel.

In the pull rod mechanism, a front retaining shoulder is arranged on a central hole of the mandrel and used for positioning the outer end surface of the inner nest; the pull rod can move axially relative to the inner nesting; and a rear nut is arranged at the rear end of the mandrel and used for axially limiting the rear end of the pull rod.

In the pull rod mechanism, the pull rod is provided with the one-way inflation device which comprises an axial channel, a radial channel, a sealing piston, a return spring and a fixed jackscrew, wherein the axial channel is arranged on a central axis of the tail end of the pull rod and can be connected with an external air supply mechanism; the radial channel is arranged along the radial direction of the pull rod and is communicated with the axial channel; the radial channel is provided with a through channel communicated with the annular air cavity; the radial channel is internally and sequentially provided with a sealing piston, a reset spring and a fixed jackscrew from inside to outside, the fixed jackscrew is supported on the inner wall of the mandrel, and the sealing piston can seal the communication position of the axial channel and the radial channel under the elastic action of the reset spring.

In the pull rod mechanism, the large-diameter end of the pull rod is provided with two groups of large sealing rings to seal the large-diameter end and the inner wall of the mandrel; two groups of small sealing rings are arranged in the inner hole of the inner nesting, and the small-diameter end and the inner hole of the inner nesting are sealed; two groups of O-shaped rings are arranged on the outer wall of the inner nesting, and sealing is formed between the outer wall of the inner nesting and the inner wall of the mandrel.

In the pull rod mechanism, the large-diameter end of the pull rod is also provided with a first oil groove which is positioned between the two groups of large sealing rings; a second oil groove is arranged in the inner hole of the inner nesting and is positioned between the two groups of small sealing rings; and hydraulic oil is filled in the first oil groove and the second oil groove.

Compared with the prior art, the utility model has the beneficial effects that: the utility model adopts compressed nitrogen to provide power, thus having clean energy and low cost; the power is supplied by compressed gas, so that the number of component parts is greatly reduced, vibration during high-speed rotation is effectively avoided, the operation stability is ensured, and the device is simple in structure and convenient to manufacture; the front end and the rear end are sealed by adopting double seals, the middle of the front end and the rear end is provided with sealing oil to form effective seal, the provided power is not attenuated along with the increase of the use times, and the broach force is stable.

Drawings

FIG. 1 is a schematic diagram of the present invention.

FIG. 2 is a schematic view of the one-way inflator of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 and 2, the pull rod mechanism of the present invention includes a pull rod 1, an inner nest 2 and a mandrel 3, wherein the mandrel 3 is a hollow structure, and the pull rod 1 is disposed in a central hole of the mandrel 3. The pull rod 1 is of a stepped shaft structure and comprises a large-diameter end and a small-diameter end, the large-diameter end is attached to the inner wall of the mandrel 3, the small-diameter end sleeve is provided with 2 embedded sleeves, the inner wall of the 2 embedded sleeves is attached to the small-diameter end of the pull rod 1, and the outer wall of the inner sleeve is attached to the inner wall of the mandrel 3. The central hole of the mandrel 3 is provided with a front retaining shoulder 17 for positioning the outer end surface of the inner nest 2. The mandrel 3 can move axially relative to the inner nest 2 under the action of external force. The rear end of the mandrel 3 is provided with a rear nut 4 which axially limits the rear end of the pull rod 1.

The inner nest 2 has a certain axial distance with the large-diameter end of the pull rod 1, so that an annular air cavity 11 is formed by the inner end face of the inner nest 2, the inner end face of the large-diameter end, the outer wall of the small-diameter end and the inner wall of the mandrel 3. The pull rod 1 is provided with a one-way inflating device which can inflate compressed nitrogen into the annular air cavity 12. The one-way inflation device comprises an axial channel 14, a radial channel 15, a through channel 16, a sealing piston 7, a return spring 8 and a fixed jackscrew 9, wherein the axial channel 14 is arranged on the central axis of the tail end of the pull rod 1 and can be connected with an external air supply mechanism, the radial channel 15 is radially arranged along the pull rod 1 and is communicated with the axial channel 14, and the through channel 16 communicated with the annular air cavity 11 is arranged on the radial channel 14. Compressed nitrogen provided by an external air supply mechanism can be filled into the annular air cavity 11 through the axial channel 14, the radial channel 15 and the through channel 16 in sequence, and the expansion force of the compressed nitrogen can tighten a cutter at the front end of the pull rod 1.

The radial channel 15 is internally and sequentially provided with a sealing piston 7, a return spring 8 and a fixed jackscrew 9 from inside to outside, the sealing piston 7, the return spring 8 and the fixed jackscrew 9 form a one-way valve structure, the fixed jackscrew 9 is supported on the inner wall of the mandrel 3, and the sealing piston 7 can seal the communication position of the axial channel 14 and the radial channel 15 under the elastic action of the return spring 8.

In order to ensure the internal gas sealing of the annular gas cavity 11, two groups of large sealing rings 5 are arranged at the large-diameter end of the pull rod 1, and the large-diameter end of the pull rod 1 is sealed with the inner wall of the mandrel 3. Meanwhile, two groups of small sealing rings 6 are arranged in the inner hole of the inner nesting 2, and the small-diameter end of the pull rod 1 and the inner hole of the inner nesting 2 are sealed. And two groups of O-shaped rings 10 are arranged on the outer wall of the inner nesting 2 to seal the space between the outer wall of the inner nesting 2 and the inner wall of the mandrel 3. The large-diameter end of the pull rod 1 is also provided with a first oil groove 12, the first oil groove 12 is arranged between the two groups of large sealing rings 5, and hydraulic oil is filled in the first oil groove 12 to lubricate the rear end seal. Meanwhile, a second oil groove 13 is formed in an inner hole of the inner nesting ring 2, the second oil groove 13 is located between the two groups of small sealing rings 6, and hydraulic oil is filled into the second oil groove 13, so that the front end can be sealed and lubricated.

When the sealing device works, compressed nitrogen with pressure is introduced into the axial channel 14 through an external air supply mechanism to push the sealing piston 7 to move outwards along the radial channel 15 and compress the return spring 8, the compressed nitrogen enters the annular air cavity 11 through the radial channel 15 and the through channel 16, the sealing piston 7 moves inwards along the radial channel 15 under the action of the return spring 8 after the pressure of the axial channel 14 is equal to that of the annular air cavity 11, and the communication part of the axial channel 14 and the radial channel 15 is resealed, so that the annular air cavity 11 is completely sealed. Under the expansion action of the compressed nitrogen, the pull rod 1 always upwards tensions a cutter at the front end of the pull rod. When the cutter at the front end of the pull rod 1 needs to be loosened, the mandrel 3 is fixed, the rear part of the pull rod 1 is pushed, the pull rod 1 moves forwards, and then the cutter at the front end can be loosened. After the tool is replaced, the external force is removed, and the pull rod 1 moves backwards under the action of the expansion force of the compressed nitrogen in the annular air cavity 11 so as to tighten the front-end tool again.

Although the present invention has been described in detail hereinabove, the present invention is not limited thereto, and those skilled in the art can make various modifications in accordance with the principle of the present invention. Thus, modifications made in accordance with the principles of the present invention should be understood to fall within the scope of the utility model.

Claims

1. A pull rod mechanism comprises a pull rod and a mandrel, wherein the mandrel is of a hollow structure, and the pull rod is arranged in a central hole of the mandrel; the device is characterized in that an annular air cavity is formed between the pull rod and the inner wall of the mandrel, and compressed nitrogen is filled in the annular air cavity; the pull rod is of a stepped shaft structure and comprises a large-diameter end and a small-diameter end, the large-diameter end is attached to the inner wall of the mandrel, the small-diameter end is sleeved with an inner nesting sleeve, the inner wall of the inner nesting sleeve is attached to the small-diameter end of the pull rod, and the outer wall of the inner nesting sleeve is attached to the inner wall of the mandrel; the annular air cavity is composed of an inner end face, a large-diameter end inner end face, a small-diameter end outer wall and a mandrel inner wall which are nested inside.

2. The pull rod mechanism of claim 1, wherein the central hole of the mandrel is provided with a front stop shoulder for positioning the outer end surface of the inner nest; the pull rod can axially move relative to the inner nest; and a rear nut is arranged at the rear end of the mandrel and used for axially limiting the rear end of the pull rod.

3. The pull rod mechanism as claimed in claim 2, wherein the pull rod is provided with a one-way inflation device which comprises an axial channel, a radial channel, a sealing piston, a return spring and a fixed jackscrew, wherein the axial channel is arranged on a central axis of the tail end of the pull rod and can be connected with an external air supply mechanism; the radial channel is arranged along the radial direction of the pull rod and is communicated with the axial channel; the radial channel is provided with a through channel communicated with the annular air cavity; the radial channel is internally and sequentially provided with a sealing piston, a reset spring and a fixed jackscrew from inside to outside, the fixed jackscrew is supported on the inner wall of the mandrel, and the sealing piston can seal the communication position of the axial channel and the radial channel under the elastic action of the reset spring.

4. The pull rod mechanism as claimed in claim 3, wherein the pull rod has two sets of large sealing rings on its large diameter end to seal the large diameter end with the inner wall of the mandrel; two groups of small sealing rings are arranged in the inner hole of the inner nesting, and the small-diameter end and the inner hole of the inner nesting are sealed; two groups of O-shaped rings are arranged on the outer wall of the inner nesting sleeve, and the outer wall of the inner nesting sleeve and the inner wall of the mandrel are sealed.

5. The pull rod mechanism of claim 4, wherein the pull rod large diameter end is further provided with a first oil groove between the two groups of large sealing rings; a second oil groove is arranged in the inner hole of the inner nesting and is positioned between the two groups of small sealing rings; and hydraulic oil is filled in the first oil groove and the second oil groove.