CN205605376U - Utilize shape memory alloy driven hydraulic pump - Google Patents

Abstract

The utility model discloses a hydraulic pump driven by a shape memory alloy. The hydraulic pump comprises a fixed support (1), a first hydraulic pump body (2A), a second hydraulic pump body (2B), and a double-headed piston (3). , a first set of shape memory alloy elements (4A), a second set of shape memory alloy elements (4B), a first set of heaters (5A), a second set of heaters (5B) and fasteners ( 6 ). It is beneficial for the heater to alternately heat the two sets of shape memory alloy elements, control the length change of the shape memory alloy elements, drive the double-headed piston to move back and forth, and realize the bidirectional driving effect. The device has simple structure and clear principle. The force of the shape memory alloy element is pure tension, and the material utilization efficiency is high. Combined with the hydraulic system, various mature technologies of the hydraulic system can be used, and it has versatility. It is especially suitable for the motion drive of various bionic robots.

Description

A hydraulic pump driven by shape memory alloy

technical field

The utility model relates to the technical field of hydraulic pumps, in particular to a hydraulic pump driven by a shape memory alloy.

Background technique

Shape memory alloy is a widely used smart material, its deformation is controlled by both stress and temperature, and its physical essence is thermoelastic martensitic transformation. When the temperature of the material is lower than the initial temperature of the transformation from martensite to austenite, the material is in the martensite phase state, the bearing capacity of the material is low, and it is easier to deform under the action of external force; and for the deformed martensite When the temperature of the tenite phase material is raised until it is higher than the completion temperature point of the transformation from martensite to austenite, the material undergoes reverse phase transformation, transforms into austenite phase, and restores its previous shape. At the same time, it can also bear Larger loads do work externally. This is the famous shape memory effect and its driving principle. Utilizing this principle of shape memory alloys, mature products such as shape memory alloy pipe joints and shape memory alloy space unlocking devices have been developed, and have been widely used.

On the other hand, the robot industry, especially the field of bionic robots is booming, and there is a very strong demand for various drives. Shape memory alloy drivers have attracted a lot of attention because of their simple structure, convenient control, and high output power, and they have occupied an important place in the field of robot drives. A number of patent applications (application number CN201210044542.X, application number CN201210041105.2, application number CN201320458623.4, application number CN201410353149.8, application number CN201510440930.3, etc.) have introduced various types of bionic robots or drivers using shape memory alloys. The existing shape memory alloy driver mainly uses shape memory alloy wire or coil spring as the driving element: the wire has a large output and high efficiency, but the stroke is small; the coil spring has a large stroke, but the efficiency is low, and the output is small. How to design a high-efficiency shape memory alloy actuator with both output and stroke has urgent practical needs and great application prospects.

The hydraulic drive system is a mature industrial technology, which usually includes power components (hydraulic pumps), actuators, control components, auxiliary components and hydraulic oil. If the shape memory alloy is used to drive the hydraulic pump, on the one hand, the structure of the hydraulic pump can be greatly simplified, and on the other hand, the relevant mature technology of the existing hydraulic system can be used to improve the driving performance of the shape memory alloy. In view of this, the patent application "Hydraulic pump using shape memory alloy" (application number CN95196561.1), and "a hydraulic device and its use" (application number CN00132784.4) both involve shape memory alloy driven hydraulic pumps. of this idea. In these two applications, the design idea of the power element is basically the same, that is, a set of shape memory alloy elements and a set of elastic elements are used to form a bias drive. When the shape memory alloy element is heated, it shrinks and compresses the elastic element to drive the piston to complete oil absorption. Action: When the shape memory alloy is cooled, the elastic element recovers, elongates the shape memory alloy element, and drives the piston to complete the oil discharge action.

The characteristic of the existing shape memory alloy hydraulic pump is that it only has the ability to drive in one direction, but it is hoped that it has the ability to work in two directions in permitted occasions such as bionic robots; in addition, the output of the elastic element in the biasing device must be Between the high output force and the low output force of the shape memory alloy element, the driving force (the high output force of the shape memory alloy element minus the output force of the elastic element, or the output force of the elastic element minus the low output force of the shape memory alloy element) must be less than the high output force of the shape memory alloy element. Due to the difference between output and low output, the driving potential of shape memory alloy materials has not been fully realized.

Utility model content

The purpose of the utility model is to provide a high-efficiency shape-memory alloy hydraulic pump with two-way driving capability.

In order to achieve the above purpose, the technical solution adopted by the utility model is: a hydraulic pump driven by a shape memory alloy, including a fixed bracket, a first hydraulic pump body, a second hydraulic pump body, a double-headed piston, a first set of shape memory Alloy elements, a second set of shape memory alloy elements, a first set of heaters and a second set of heaters; wherein,

The double-headed piston can be divided into three parts in the axial direction. There is a piston head at each end of the double-headed piston. There is a protruding flange in the middle of the double-headed piston. One ends of the two sets of shape memory alloy elements are respectively fixedly connected;

One end of each hydraulic pump body in the first hydraulic pump body and the second hydraulic pump body is an open end, the open end of the first hydraulic pump body is opposite to the open end of the second hydraulic pump body, and the two piston heads of the double-headed piston Cooperate with the inner surface of the opening end of the first hydraulic pump body and the second hydraulic pump body respectively. There is an oil port in the middle of the other end of each hydraulic pump body, and the oil port at the end of each hydraulic pump body has the oil port. There is also a flange around the body, the flange of the first hydraulic pump body and the flange of the second hydraulic pump body are used to install the fixing bracket, and the flange of the first hydraulic pump body is used to install the second hydraulic pump body The other end of a group of shape memory alloy elements, the flange of the second hydraulic pump body is used to install the other end of the second group of shape memory alloy elements;

The first group of shape memory alloy elements and the second group of shape memory alloy elements are tensile elements;

The first group of heaters is covered on the surface of the first group of shape memory alloy elements, and the second group of heaters is covered on the surface of the second group of shape memory alloy elements.

Wherein, the hydraulic pump further includes fasteners, which are used to fasten the fixing bracket, the first set of shape memory alloy elements and the second set of shape memory alloy elements.

Wherein, the tensile element can be a wire, a strip, a stranded wire or a rod, and it must undergo a certain pre-stretching before installation, and one end is fixed on a flange of a hydraulic pump body during installation. The other end is connected with the flange of the double-ended piston.

Wherein, the first group of heaters and the second group of heaters can specifically adopt resistance heating, induction current heating or other existing heating methods.

The utility model advantage and positive effect are:

The device has simple structure and clear principle. The force of the shape memory alloy element is pure tension, and the material utilization efficiency is high. Two sets of shape memory alloy elements are used to realize bidirectional repeated driving. Combined with the hydraulic system, various mature technologies of the hydraulic system can be used, and it has versatility. It is especially suitable for the motion drive of various bionic robots.

Description of drawings

Fig. 1 is a schematic structural diagram of a hydraulic pump driven by a shape memory alloy;

Figure 2 is a double-acting executive hydraulic cylinder used in conjunction with the hydraulic pump;

Figure 3 is a single-acting executive hydraulic cylinder used in conjunction with the hydraulic pump;

The meanings of reference signs in the figure are: 1-fixed bracket, 2A-first hydraulic pump body, 2B-second hydraulic pump body, 21A-oil port of first hydraulic pump body, 21B-oil port of second hydraulic pump body , 3-double-headed piston, 31A-the first piston head of the double-headed piston, 31B-the second piston head of the double-headed piston, 4A-the first set of shape memory alloy elements, 4B-the second set of shape memory alloy elements, 5A -The first set of heaters, 5B-the second set of heaters, 6-fasteners, 7-piston of single-acting hydraulic cylinder, 7#-piston of double-acting hydraulic cylinder, 8-oil port of single-acting hydraulic cylinder, 8A-the first port of the double-acting hydraulic cylinder, 8B-the second port of the double-acting hydraulic cylinder, 9-spring.

detailed description

Further illustrate the utility model below in conjunction with accompanying drawing and specific embodiment.

As shown in Figure 1, the utility model is a hydraulic pump driven by shape memory alloy, which includes a set of fixed bracket 1, a first hydraulic pump body 2A, a second hydraulic pump body 2B, a double-headed piston 3, and a first set of shape memory alloy Element 4A, the second group of shape memory alloy elements 4B, the first group of heaters 5A, the second group of heaters 5B and fasteners 6 and other parts.

The double-headed piston 3 can be divided into three parts in the axial direction, each with a piston head 31A, 31B at both ends, and the piston heads 31A, 31B cooperate with the corresponding parts of the first hydraulic pump body 2A and the second hydraulic pump body 2B respectively, The protruding flange in the middle can be connected and fixed with the first group of shape memory alloy elements 4A and the second group of shape memory alloy elements 4B on both sides.

One end of the first hydraulic pump body 2A and the second hydraulic pump body 2B is an open end, the inner surfaces of which are respectively matched with the piston head 31A and the piston head 31B of the double-headed piston 3, and there is an oil port 21A and an oil port in the middle of the other end respectively. Port 21B, around this end of oil port 21A, there are mounting brackets 1 and flanges for the first group of shape memory alloy elements 4A, and around this end of oil port 21B, there are mounting brackets 1 and a second group of shape memory alloy elements 4B flange. The first hydraulic pump body 2A and the second hydraulic pump body 2B are mounted on the same set of fixed brackets 1 , with their open ends facing each other.

The first group of shape-memory alloy elements 4A and the second group of shape-memory alloy elements 4B are tensile elements, which can be wires, strips, strands or rods. Before installation, they must first undergo a certain pre-stretching. One end is respectively fixed on the flange of the first hydraulic pump body 2A and the second hydraulic pump body 2B, and one end is connected with the flange of the double-headed piston 3 .

The first group of heaters 5A and the second group of heaters 5B are respectively coated on the surfaces of the first group of shape memory alloy elements 4A and the second group of shape memory alloy elements 4B. Specifically, resistance heating, induction current heating or other methods can be used. Some heating methods.

The hydraulic pump driven by the shape memory alloy generally needs to be used with a double-acting hydraulic cylinder, as shown in Figure 2. There is an oil port 8A at one end of the double-acting executive hydraulic cylinder, and an oil port 8B at the other end. The oil port 8A and the oil port 8B pass through the pipeline and the oil port 21A of the first hydraulic pump body 2A and the oil of the second hydraulic pump body 2B respectively. port 21B connection. The piston 7# of the double-acting hydraulic cylinder moves between the two oil ports 8A and 8B, and the ratio of the effective areas on both sides of the piston 7# of the double-acting hydraulic cylinder is equal to the ratio of the effective areas on both sides of the double-headed piston 3 . When in use, first connect the pipes to ensure that all cavities are filled with hydraulic oil and sealed. Initially, the ambient temperature is lower than the initiation temperature of the transformation from martensite to austenite, and the two sets of shape memory alloy elements 4A and 4B are in a low output state. For example, the first group of shape-memory alloy elements 4A are heated by the first group of heaters 5A, the first group of shape-memory alloy elements 4A heat up, phase change and shrink, and transform into a state of high output force, so the shape of the second group can be elongated The memory alloy element 4B drives the double-headed piston 3 to move to the A side, prompting the hydraulic oil in the first hydraulic pump body 2A on this side to discharge from the oil port 21A, and enter from the oil port 8A of the double-acting hydraulic cylinder through the connecting pipeline. , to push the piston 7# of the double-acting hydraulic cylinder to move to one side to realize the driving function; at the same time, part of the hydraulic oil on the other side of the piston 7# of the double-acting hydraulic cylinder passes through the oil port 8B, and the connecting pipe and oil port 21B return to the second hydraulic pump body 2B. Stop the first group of heaters 5A, the first group of shape memory alloy elements 4A is cooled to the initial low output state, and then the second group of shape memory alloy elements 4B is heated by the second group of heaters 5B to realize reverse driving. By repeating the above process, continuous reciprocating drive can be realized.

The hydraulic pump driven by the shape memory alloy can simultaneously drive multiple double-acting hydraulic cylinders. The ratio of the sum of the effective areas on both sides of the piston 7# of each double-acting hydraulic cylinder must be equal to the ratio of the effective areas on both sides of the double-headed piston 3 of the hydraulic pump connected thereto.

Other embodiments: the hydraulic pump driven by a shape memory alloy can also be used in conjunction with a single-acting hydraulic cylinder, as shown in FIG. 3 . The single-acting hydraulic cylinder has only one oil port 8, and the reset of the piston 7 of the single-acting hydraulic cylinder depends on the spring 9 or gravity. During use, connect a certain hydraulic pump body such as the oil port 21A of the hydraulic pump body 2A and the oil port 8 of the single-acting hydraulic cylinder, and fill it with hydraulic oil, while the other hydraulic pump body 2B is not filled with oil. Alternately heating the two sets of shape memory alloy elements 4A, 4B can realize the action and return of the single-acting executive hydraulic cylinder. Apparently, the hydraulic pump driven by the shape memory alloy can also simultaneously drive multiple single-acting hydraulic cylinders, which will not be repeated here.

Claims (4)

1. A hydraulic pump driven by a shape memory alloy, characterized in that: the hydraulic pump comprises a fixed support (1), a first hydraulic pump body (2A), a second hydraulic pump body (2B), a double-head piston (3), a first group of shape memory alloy elements (4A), a second group of shape memory alloy elements (4B), a first group of heaters (5A) and a second group of heaters (5B); wherein,

the double-end piston (3) can be divided into three parts in the axial direction, two ends of the double-end piston (3) are respectively provided with a piston head, and a protruding flange plate is arranged in the middle of the double-end piston (3) and can be respectively and fixedly connected with one end of a first group of shape memory alloy elements (4A) and one end of a second group of shape memory alloy elements (4B) at two sides;

one end of each of the first hydraulic pump body (2A) and the second hydraulic pump body (2B) is an open end, the open end of the first hydraulic pump body (2A) is opposite to the open end of the second hydraulic pump body (2B), two piston heads of the double-head piston (3) are respectively matched with the inner surfaces of the open ends of the first hydraulic pump body (2A) and the second hydraulic pump body (2B), an oil port is arranged in the middle of the other end of each hydraulic pump body, a flange plate is arranged around the oil port at the end with the oil port on each hydraulic pump body, the flange plate of the first hydraulic pump body (2A) and the flange plate of the second hydraulic pump body (2B) are used for installing a fixed support (1), and the flange of the first hydraulic pump body (2A) is used for mounting the other end of the first group of shape memory alloy elements (4A), and the flange of the second hydraulic pump body (2B) is used for mounting the other end of the second group of shape memory alloy elements (4B);

the first group of shape memory alloy elements (4A) and the second group of shape memory alloy elements (4B) are all stretching elements;

the first group of heaters (5A) covers the surface of the first group of shape memory alloy elements (4A), and the second group of heaters (5B) covers the surface of the second group of shape memory alloy elements (4B).

2. The hydraulic pump driven by the shape memory alloy as set forth in claim 1, wherein: the hydraulic pump further comprises a fastener (6), the fastener (6) being used to fasten the stationary support (1), the first set of shape memory alloy elements (4A) and the second set of shape memory alloy elements (4B).

3. The hydraulic pump driven by the shape memory alloy as set forth in claim 1, wherein: the stretching element can be wire material, strip material, stranded wire or bar material, before installation, a certain pretension is needed, one end of the stretching element is fixed on a flange of a hydraulic pump body, and the other end of the stretching element is connected with the flange of the double-head piston.

4. The hydraulic pump driven by the shape memory alloy as set forth in claim 1, wherein: the first group of heaters (5A) and the second group of heaters (5B) can adopt resistance heating, induction current heating or other existing heating modes.