WO2015188647A1

WO2015188647A1 - Single-acting pressure cylinder

Info

Publication number: WO2015188647A1
Application number: PCT/CN2015/075470
Authority: WO
Inventors: 吴建友; 钟康民; 窦云霞
Original assignee: 苏州劳灵精密机械有限公司
Priority date: 2014-06-12
Filing date: 2015-03-31
Publication date: 2015-12-17
Also published as: DE112015000735T5

Abstract

Disclosed is a single-acting pressure cylinder comprising a cylinder body (1), a front end cover (2), a rear end cover (3), and a piston rod (4). An inner bore (41) is provided on the piston rod (4) and extends in the axial direction thereof. A sliding element (5) is slidably inserted into the inner bore (41) from the rear extremity of the piston rod (4). The rear extremity of the sliding element (5) is fixedly connected to the rear end cover (3). Arranged in the inner bore (41) is a return spring (7) used for providing the piston rod (4) with a resetting force. The return spring (7) is arranged between the sliding element (5) and the piston rod (4). The single-acting pressure cylinder can be used either as a single-acting hydraulic cylinder or as a single-acting pneumatic cylinder, has a simple structure, reduced axial dimension, great assembly manufacturability, and inexpensive manufacturing costs, and provides increased mechanical efficiency.

Description

Single acting pressure cylinder

Technical field

The invention relates to a single acting pressure cylinder, in particular a single acting pneumatic cylinder or hydraulic cylinder.

Background technique

Single-acting cylinders and hydraulic cylinders, compared with double-acting cylinders and hydraulic cylinders, have a simple structure and low cost. The main reason is that a single-acting cylinder or hydraulic cylinder requires only one pipe for entering or leaving gas or liquid, and a double-acting cylinder or hydraulic cylinder. The cylinder needs two. In addition, a static sealing device is required between the front end cover of the double-acting cylinder and the hydraulic cylinder and the cylinder barrel, and a dynamic sealing device is also required between the piston rod and the inner hole of the front end cover, as shown in FIG.

The basic structure of the conventional single-acting cylinder and hydraulic cylinder is shown in Fig. 2. The most prominent disadvantage is that the return spring generally needs about one-third of the axial space, which causes the axial dimension of the cylinder to increase. This not only wastes material, but also significantly increases costs.

Therefore, the innovation of a single-acting cylinder and hydraulic cylinder in which the return spring does not occupy the axial space has a very positive significance for reducing the axial dimension and reducing the production cost. In addition, the economics of hydraulic and pneumatic transmission systems for industrial applications can be increased accordingly.

In order to design a single-acting cylinder and a hydraulic cylinder in which the return spring does not occupy the axial space, it is relatively easy to think of a technical solution in which a tension return spring is provided in the inner hole of the piston rod, such as the Chinese invention patent application number 102979781A, in which A single-acting plunger cylinder using a spring-loaded reset is proposed, the structure of which is shown in FIG. This type of single-acting cylinder has the following significant disadvantages: (1) Due to the use of the tension spring, it is necessary to provide a spring hooking device on the piston rod and the rear end cover, which not only causes the machining processability of the relevant parts. Well, and the assembly of the spring is extremely inconvenient; (2) due to the tension spring used, its mechanical properties are linear, that is, the spring's restoring force is proportional to its deformation, so the minimum return force and maximum reset force of the spring There is a large difference, resulting in unnecessary waste of force, correspondingly reducing the mechanical efficiency of the cylinder or hydraulic cylinder.

Summary of the invention

It is an object of the present invention to provide a single-acting pressure cylinder having a small axial dimension and high mechanical efficiency, which has a simple structure and good assembly processability.

In order to achieve the above object, the technical solution adopted by the present invention is: a single-acting pressure cylinder comprising a cylinder block, a front end cover and a rear end cover fixed to the cylinder block, a piston rod inserted in the cylinder body, and a piston rod An inner hole is defined in an axial direction thereof, a sliding member is slidably inserted into the inner hole from a rear end of the piston rod, and a rear end of the sliding member is fixedly connected to the rear end cover, and the inner hole is disposed in the inner hole And a return spring that provides a restoring force to the piston rod, the return spring being arranged between the sliding member and the piston rod.

In a specific example, the slider is a guide rod assembly including a rod body and a large diameter end fixedly disposed at a front end of the rod body, the rear end of the rod body being fixedly coupled to the rear end cover The piston rod is fixedly coupled to the rear end of the inner hole with a cover having a socket, wherein the cover forms an annular space with the large diameter end, and the return spring is located in the annular space. Inside.

Further, the return spring is a compression spring. The compression spring is used as the return spring, and its rigidity has a larger selection range than the general coil spring.

Further, the return spring is preferably a nonlinear butterfly spring, and due to its non-linear characteristics, the restoring force of the spring can be controlled within a small range.

Further, a return spring is sleeved on the rod.

Further, the large diameter end is integrally provided with the rod body, or the large diameter end is fixedly connected to the rod body.

Specifically, the inner hole on the piston rod is a through hole, and the piston rod is fixedly connected with the force output element at the front end of the inner hole.

In another specific example, the slider is a spool, and a closed space is formed between the front end of the spool and the inner bore, and the return spring is located in the closed space.

Further, the inner hole of the piston rod is a through hole, and a front end of the piston rod is fixedly connected with a force output element, and the return spring is located between the force output element and the spool.

Due to the use of the above technical solutions, the present invention has the following advantages over the prior art: the single-acting pressure cylinder of the present invention can be used for a single-acting hydraulic cylinder or a single-acting pneumatic cylinder, wherein the return spring is placed inside the piston rod In the hole, it is not necessary to occupy the axial space of the hydraulic cylinder or the pneumatic cylinder, thereby greatly reducing the axial size of the cylinder, and significantly reducing the manufacturing cost. The diameter of the cylinder is greatly reduced compared with the prior art, and the mechanical efficiency of the single-acting thrust cylinder is effectively improved, so that it has good energy saving.

DRAWINGS

1 is a schematic view showing the working principle of a double-acting cylinder in the prior art;

2 is a schematic view showing the working principle of a conventional single-acting thrust cylinder in the prior art;

3 is a schematic view showing the working principle of a single-acting plunger cylinder using a tension spring reset in the prior art;

Figure 4 is a first schematic diagram showing the working principle of a single-acting pressure cylinder according to a first embodiment of the present invention;

Figure 5 is a second schematic diagram of the working principle of the single-acting pressure cylinder according to the first embodiment of the present invention;

Figure 6 is a third schematic diagram of the working principle of the single-acting pressure cylinder according to the first embodiment of the present invention;

Figure 7 is a schematic view showing the internal structure of a single-acting pressure cylinder according to a second embodiment of the present invention;

Figure 8 is a second internal schematic view of a single-acting pressure cylinder according to a second embodiment of the present invention;

Figure 9 is a third internal structural view of a single-acting pressure cylinder according to a second embodiment of the present invention.

Wherein: 1, cylinder; 2, front end cover; 21, first hole; 3, rear end cover; 31, second hole; 4, piston rod; 41, inner hole; 5, guide rod assembly; 51, rod body; 52, large diameter end; 6, cover; 61, jack; 7, return spring; 8, electromagnetic reversing valve; 9, force output components.

detailed description

The technical solutions of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

Example 1

Referring to the single-acting cylinder shown in FIG. 4, FIG. 5 and FIG. 6, specifically, the pressure cylinder in this embodiment is a single-acting thrust cylinder, and includes a cylinder block 1, and a front end cover 2 disposed at the front of the cylinder block 1. A rear end cover 3 provided at the rear of the cylinder block 1 and a piston rod 4 provided in the cylinder block 1 movable in the front-rear direction, wherein the front end of the piston rod 4 passes outside the front end cover 2.

The above and below definitions of the directions are defined by the direction in which the piston rod 4 moves when the thrust cylinder is in operation. The direction in which the piston rod 4 moves outward relative to the cylinder block 1 is the front, and vice versa, that is, FIG. In the left and right direction in Fig. 9, the left side is the rear and the right side is the front side.

The piston rod 4 is provided with an inner hole 41, and the front portion of the inner hole 41 is closed. Here, the inner bore 41 is provided as a through hole, and the front end of the piston rod 4 is fixedly provided with a force output member 9 which closes the front portion of the inner bore 41. Thus, by sealingly connecting the rear end cover 3 to the cylinder block 3, a closed pressure chamber can be formed between the rear end cover 3, the piston rod 4 and the cylinder block 1.

A sliding member 5 is bored in the inner hole 41. The sliding member in the present example is a guiding rod assembly including a rod body 51 and a large diameter end 52 fixedly disposed at the front end of the rod body 51, the rod body 51 and the large diameter The ends 52 can be integrally formed, and the two can be separately disposed and fixedly coupled together by screws or other components. The rear end of the rod body 51 is fixedly coupled to the rear end cover 3, and the rear end of the inner hole 41 of the piston rod 4 is fixedly coupled to the door cover 6, and the door cover 6 has an insertion hole 61 for the rod body 51 to pass therethrough. An annular space is formed between the cover 6 and the large diameter end 52 in the inner bore 41, and a return spring 7 is provided in the annular space. Specifically, in the present embodiment, the return spring 7 employs a compression spring.

Referring to Fig. 4, in the initial state, under the action of the thrust of the return spring 7, the piston of the piston rod 4 is located at the rear of the cylinder 1, when the compressed gas/hydraulic oil passes through the rear end cover 3 as the intake air. When the second hole 31 of the hole/oil inlet hole enters the pressure chamber, the piston rod 4 moves forward, and the single-acting thrust cylinder outputs forward thrust, and the return spring 7 is pressed against the cover 6 and the large diameter. Between the ends 52, as shown in FIG.

When the piston rod 4 moves forward, the compressed gas in the pressure chamber flows into the atmosphere or the hydraulic oil returns to the oil tank, and under the action of the thrust of the return spring 7, the piston rod 4 is pushed backward, as shown in FIG. Complete the reset. The above process can be realized by the commutation operation of the electromagnetic reversing valve 8.

Referring to the drawings, the front end cover 2 is also provided with a first hole 21 as a breathing hole, so that the space between the piston rod 4 and the front end cover 2 communicates with the outside, so that the smooth movement of the piston rod 4 can be ensured. The air pressure formed in the above space is prevented from forming a resistance to the forward and backward movement of the piston rod 4.

In the present embodiment, the return spring 7 employs a nonlinear butterfly spring which is sleeved on the rod body 51 in the above-mentioned annular space. Since the mechanical properties of the butterfly spring are nonlinear, when the butterfly spring is selected, a reasonable mechanical characteristic interval can be selected according to the working conditions of the actual application, so that the variation range of the spring restoring force can be greatly reduced, and the single can be effectively improved. The mechanical efficiency of the thrust cylinder is conducive to energy saving. The traditional tension coil spring is linear because its mechanical characteristics are linear, and its stiffness is proportional to its deformation. When the deformation amount is large, the restoring force is significantly increased, and this resetting force needs to consume the piston to provide additional force. Overcoming, it is bound to cause the cylinder bore to expand under certain conditions of system pressure. The present invention solves this problem well, and the diameter of the cylinder body is further reduced compared with the prior art.

In addition, the butterfly spring can be in the form of a lamination to increase the rigidity, which makes the thrust of the thrust cylinder output of the present invention have a larger adjustment range, so that it has better versatility.

In summary, the single-acting thrust cylinder of the present invention can be used as a single-acting hydraulic cylinder or a single-acting pneumatic cylinder, wherein the reset spring 7 is used to reset, and the return spring 7 does not need to occupy the axial space of the thrust cylinder, thereby The axial dimension of the cylinder block 1 is greatly reduced, material is saved, and the manufacturing cost is remarkably reduced. The resetting force of the return spring 7 used has a small range of variation, which effectively improves the mechanical efficiency of the single-acting thrust cylinder, and has good energy saving. In addition, in the thrust cylinder, only the static seal between the rear end cover 3 and the cylinder block 1 and the dynamic seal between the piston rod 4 and the cylinder block 1 are required to be sealed, and the structure is simpler and the assembly is simpler. Good assembly processability.

Example 2

Referring to FIG. 7-9, specifically, the pressure cylinder in this embodiment is a single-acting tension cylinder, and the embodiment is similar to the structure of the first embodiment. The main difference is that the sliding member 5 in the embodiment is a sliding column. A closed space is formed between the front end of the strut and the force output member 9, and the return spring 7 is located in the closed space.

Unlike the structure of Embodiment 1, the rear end of the inner hole 41 of the piston rod 4 in this embodiment is not provided with a stopper.

In addition, the embodiment also has some differences in Embodiment 1, such as: the second hole 31 on the rear end cover 3 serves as a breathing hole, so that the space between the piston rod 4 and the rear end cover 3 communicates with the outside, such that The smooth movement of the piston rod 4 can be ensured, and the air pressure formed in the above space can be prevented from forming a resistance to the forward and backward movement of the piston rod 4. At the same time, the spool 5 is provided with a through hole extending in the axial direction thereof, and the rear portion of the spool 5 has an opening, the opening allows the through hole to communicate with the breathing hole 31 in an air flow direction, and the front end of the spool 5 and the force output member 9 are avoided. The pressure in the enclosed space formed between the rear ends creates resistance to the forward and backward movement of the piston rod 4. The first hole 21 on the front end cover 2 serves as an intake hole/oil hole.

The above embodiments are merely illustrative of the technical concept and the features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the present invention and to implement the present invention, and the scope of the present invention is not limited thereto. Equivalent variations or modifications made in accordance with the spirit of the invention are intended to be included within the scope of the invention.

Claims

1. A single-acting pressure cylinder includes a cylinder block, a front end cover and a rear end cover fixed to the cylinder block, and a piston rod inserted in the cylinder body, wherein the piston rod is opened in the axial direction thereof a hole, a sliding member is slidably inserted into the inner hole from a rear end of the piston rod, a rear end of the sliding member is fixedly coupled to the rear end cover, and the inner hole is provided with a hole for providing the piston rod A return spring that resets the force, the return spring being arranged between the slider and the piston rod.

2. A single-acting cylinder according to claim 1, wherein said sliding member is a guide rod assembly, said guide rod assembly comprising a rod body and a large-diameter end fixedly disposed at a front end of said rod body, said rod body The rear end is fixedly connected to the rear end cover, and the piston rod is fixedly connected to the rear end of the inner hole with a cover having a socket, and the cover and the large diameter end are in the inner hole The head forms an annular space in which the return spring is located.

3. The single acting cylinder of claim 2 wherein the return spring is a compression spring.

The single-acting pressure cylinder according to any one of claims 1 to 3, characterized in that the return spring is a nonlinear butterfly spring.

5. The single-acting pressure cylinder according to claim 2, wherein the return spring is sleeved on the rod body.

6. The single-acting pressure cylinder according to claim 2, wherein the large-diameter end is integrally provided with the rod body, or the large-diameter end is fixedly connected to the rod body.

7. The single-acting pressure cylinder according to claim 1, wherein said inner hole on said piston rod is a through hole, and said piston rod is fixedly coupled to a force output member at a front end of said inner hole.

8. The single-acting pressure cylinder according to claim 1, wherein the sliding member is a sliding column, and a closed space is formed between a front end of the sliding column and the inner hole, and the return spring is located in the closed space. in.

9. A single-acting tension cylinder according to claim 8, wherein said inner hole of said piston rod is a through hole, and a front end of said piston rod is fixedly coupled with a force output member, said return spring being located at said force Between the output member and the spool.