A hydraulic bearing device and a force sensor

Abstract

The present invention relates to a hydraulic bearing device and a force sensor, wherein the force sensor comprises a first piston and a second piston, wherein the first piston and the second piston have piston guide sections with the same diameter, wherein a movable cylinder is provided on the piston guide sections of the first piston and the second piston, and wherein the sealing guide movable sleeve is provided on the movable cylinder relative to the first piston and the second piston and axially moving along the piston guide section, wherein a force sensor is provided in series on the transmission path between the driving mechanism and the movable cylinder, wherein the first piston, the second piston and the movable cylinder form a hydraulic cavity, and wherein the force sensor further comprises a pressure sensor connected to the hydraulic cavity. The present invention solves the technical problem in the prior art that the measurement result is unstable due to the static friction between the piston and the cylinder body.

Description

Technical Field

[0001] The invention relates to a hydraulic bearing device and a force sensor in the field of mechanics. Background Art

[0002] In the field of mechanics, force sensors are needed to measure the output force values ​​of various tools.

[0003] For example, when detecting the output pressure of a press, a commonly used force sensor includes a hydraulic cylinder, which includes a cylinder body and a piston that seals and moves with the cylinder body. The cylinder body is provided with a pressure sensor for detecting the pressure of the liquid in the cylinder body. When calibrating the output pressure of the press, the pressure head of the press applies pressure to the piston, and the pressure sensor measures the pressure of the liquid in the cylinder body. The force on the piston, i.e., the output pressure of the press, is then converted based on the effective release area between the piston and the liquid, thereby detecting the output of the press.

[0004] The problem with this type of force sensor in the prior art is that when the press machine applies pressure to the piston, static friction is generated between the piston and the cylinder body. On the one hand, the existence of static friction will affect the measurement reading. Another characteristic of static friction is instability, which makes the reading of the pressure sensor also unstable, and ultimately makes the measurement value more inaccurate. Summary of the invention

[0005] The object of the present invention is to provide a hydraulic bearing device and a force sensor to solve the technical problem in the prior art that the measurement result is unstable due to the static friction between the piston and the cylinder body.

[0006] In order to solve the above technical problems, the technical solution of the force sensor in the present invention is as follows:

[0007] A force sensor comprises a first piston and a second piston, wherein the first piston and the second piston have piston guide sections with the same diameter, and the piston guide sections on the first piston and the second piston are sealed and guided to move with moving parts, and the force sensor also comprises a driving mechanism for driving the moving parts to move axially relative to the first piston and the second piston along the piston guide sections, and a force sensor is arranged in series on the transmission path between the driving mechanism and the moving cylinder, and the first piston and the second piston have the following two arrangement forms: in the first form, the piston guide section is arranged on the outer peripheral surface of the first piston and the second piston, and the moving parts are sleeved on the first piston and the second piston The first type is a movable cylinder, the first piston, the second piston and the movable cylinder form a hydraulic cavity, and the force sensor also includes a pressure sensor connected to the hydraulic cavity; the second type is that the first piston and the second piston have a guide inner hole, the piston guide section is arranged on the hole wall of the guide inner hole, the movable component is a movable core inserted on the first piston and the second piston, a first piston cavity is formed between one end of the movable core and the first piston, and a second piston cavity is formed between the other end of the movable core and the piston, the movable core has a movable core channel connecting the first piston cavity and the second piston cavity, and the force sensor also includes a pressure sensor connected to the first piston cavity or the second piston cavity.

[0008] The movable cylinder and the first piston are sealed by a first sealing ring, and the movable cylinder and the second piston are sealed by a second sealing ring. The materials, inner diameter and outer diameter of the first sealing ring and the second sealing ring are the same.

[0009] The driving mechanism drives the movable cylinder to move axially at a uniform speed along the piston guide section.

[0010] The effective pressure-bearing area between one end of the moving core and the first piston chamber is equal to the effective pressure-bearing area between the other end of the moving core and the second piston chamber.

[0011] The moving core channel penetrates the moving core along the moving core axial direction, and the moving core channel is an equal-diameter channel with the same diameter along the extending direction of the channel.

[0012] The moving core and the first piston are sealed by a first sealing ring, and the moving core and the second piston are sealed by a second sealing ring. The materials, inner diameter and outer diameter of the first sealing ring and the second sealing ring are the same.

[0013] The technical solution of the hydraulic bearing device in the present invention is:

[0014] A hydraulic bearing device comprises a first piston and a second piston, wherein the first piston and the second piston have piston guide sections with the same diameter, and the piston guide sections on the first piston and the second piston are sealed and guided and movable with moving parts, and a force sensor also comprises a driving mechanism for driving the moving parts to move axially relative to the first piston and the second piston along the piston guide sections, and a force sensor is serially arranged on the transmission path between the driving mechanism and the moving cylinder tube, and the first piston and the second piston have the following two arrangement forms: in the first form, the piston guide section is arranged on the outer peripheral surface of the first piston and the second piston, and the moving part is a moving cylinder tube sleeved on the first piston and the second piston, and the first piston, the second piston and the moving cylinder tube form a hydraulic cavity; in the second form, the first piston and the second piston have a guiding inner hole, and the piston guide section is arranged on the hole wall of the guiding inner hole, and the moving part is a moving core inserted on the first piston and the second piston, and a first piston cavity is formed between one end of the moving core and the first piston, and a second piston cavity is formed between the other end of the moving core and the piston, and a moving core channel connecting the first piston cavity and the second piston cavity is provided on the moving core.

[0015] The movable cylinder and the first piston are sealed by a first sealing ring, and the movable cylinder and the second piston are sealed by a second sealing ring. The materials, inner diameter and outer diameter of the first sealing ring and the second sealing ring are the same.

[0016] The driving mechanism drives the movable cylinder to move axially at a uniform speed along the piston guide section.

[0017] The effective pressure-bearing area between one end of the moving core and the first piston chamber is equal to the effective pressure-bearing area between the other end of the moving core and the second piston chamber.

[0018] The moving core channel penetrates the moving core along the moving core axial direction, and the moving core channel is an equal-diameter channel with the same diameter along the extending direction of the channel.

[0019] The moving core and the first piston are sealed by a first sealing ring, and the moving core and the second piston are sealed by a second sealing ring. The materials, inner diameter and outer diameter of the first sealing ring and the second sealing ring are the same.

[0020] The beneficial effects of the present invention are as follows: when the force sensor in the present invention is performing detection, the detected device applies force to the first piston or the second piston, and the driving mechanism drives the moving part to move axially relative to the first piston and the second piston, and dynamic friction is generated between the moving part and the first piston and the second piston. The dynamic friction can be calculated by the indication of the force sensor. Compared with static friction, dynamic friction is more stable and easier to measure.

[0021] Specifically, since the size of the piston guide section of the first piston and the second piston is the same, the friction between the movable cylinder and the first piston and the second piston is the same, and half of the value indicated by the force sensor is the friction between the movable cylinder and the corresponding piston. Then, according to the reading of the pressure sensor, the force exerted on the corresponding piston can be calculated, that is, the output force of the detected device. The present invention has the following characteristics: 1. The dynamic friction between the movable cylinder sleeve and the first piston and the second piston is easy to be measured by the force sensor; 2. Since the diameter of the piston guide section of the first piston and the second piston is the same, when the movable cylinder moves, the movable cylinder sleeve is sleeved on the outer periphery of the first piston and the second piston. When the movable cylinder sleeve moves relative to the first piston and the second piston, the movable cylinder sleeve will not exert force on the liquid in the piston cavity. The liquid pressure in the piston cavity is stable, and there is no need to compensate the liquid in the piston cavity. The movable cylinder sleeve is only subjected to friction. On the one hand, the force exerted on the movable cylinder sleeve is reduced, making the movement of the movable cylinder sleeve more convenient and reducing the energy consumption of the driving mechanism. On the other hand, the friction between the movable cylinder sleeve and the corresponding piston can be obtained more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of embodiment 1 of the force sensor of the present invention;

[0023] Figure 2 It is a schematic structural diagram of embodiment 2 of the force sensor in the present invention. DETAILED DESCRIPTION

[0024] Embodiment 1 of the force sensor of the present invention is as follows Figure 1 : It includes a hydraulic bearing device and a pressure sensor. The hydraulic bearing device includes a first piston 1 and a second piston 10 arranged up and down 14. The upper end of the first piston is used to cooperate with the equipment to be detected. The first piston and the second piston have piston guide sections 4 with the same diameter. The sealing guide moving sleeve on the piston guide section 4 of the first piston and the second piston is equipped with a moving part 3. The moving part in this embodiment is a moving cylinder. The force sensor also controls a driving mechanism that drives the moving cylinder to move at a uniform speed along the axial direction of the piston guide section relative to the first piston and the second piston. In this embodiment, the driving mechanism includes two vertically arranged synchronous electric push rods 7, and a force sensor 6 is arranged between each electric push rod 7 and the bottom outward edge 5 of the moving cylinder.

[0025] The first piston 1, the second piston 10 and the movable cylinder barrel form a hydraulic chamber 17. In this embodiment, the second piston is provided with a first oil passage 12, a second oil passage 13 and a third oil passage 11, the pressure sensor 14 is connected to the first oil passage to achieve connection with the hydraulic chamber, the second oil passage 13 constitutes a detection oil port, when the piston pressure gauge 15 needs to be calibrated, it is connected to the piston pressure gauge through the detection oil port; the third oil passage constitutes an oil supply port, before the present force sensor is used, the hydraulic pump 8 fills the hydraulic chamber with hydraulic oil through the third oil passage 11.

[0026] The piston guide sections of the first piston and the second piston are sealed with the movable cylinder sleeve by the same sealing structure. In the present embodiment, the sealing structure is a sealing ring, i.e., the movable cylinder barrel and the first piston are sealed by a first sealing ring 2, and the movable cylinder barrel and the second piston are sealed by a second sealing ring 16. The materials, inner diameter and outer diameter of the first sealing ring and the second sealing ring are the same.

[0027] When it is necessary to detect the output pressure of the corresponding equipment, for example, when testing a press, the pressure head of the press applies pressure to the upper end of the first piston, and the driving mechanism moves the movable cylinder sleeve upward (or downward) at a uniform speed along the first piston and the second piston. The pressure F exerted on the movable cylinder sleeve is the output pressure of the press. The friction force f1 between the movable cylinder sleeve and the first piston, and the force f2 exerted by the liquid on the first piston, then f1+f2=F, f2=P*S, where P is the liquid pressure in the hydraulic chamber, measured by the pressure sensor, and S is the effective pressure area of ​​the first piston in contact with the liquid. f1 can be calculated through the indication of the force sensor, because for the movable cylinder sleeve, it is subjected to the force of the driving mechanism and the friction between the first piston and the second piston. Since the diameters of the piston guide sections of the first piston and the second piston are the same, and the sealing structures between the movable cylinder sleeve and the first piston and the second piston are the same, the sum of the readings of each force sensor is equal to twice f1, and f1 can be accurately and easily calculated.

[0028] In the present invention, the movable cylinder sleeve is sleeved on the outer periphery of the first piston and the second piston, and the cross-sectional area of ​​the relative parts of the first piston and the second piston is the same. Therefore, during the movement of the movable cylinder sleeve, it is not subject to the hydraulic pressure, but only to the friction force. On the one hand, it can reduce the driving force required for the movement of the movable cylinder sleeve, reduce energy consumption, and also make the friction between the movable cylinder sleeve and the corresponding piston more accurately and conveniently obtain. In other embodiments of the present invention: the movable cylinder sleeve can also move at a non-uniform speed when moving relative to the first piston and the second piston. At this time, an acceleration sensor is set on the transmission path between the driving mechanism and the movable cylinder sleeve, and the force exerted on the movable cylinder sleeve is calculated by the readings of the acceleration and force sensor; the electric push rod can also be replaced by other driving mechanisms such as hydraulic cylinders and pneumatic cylinders that can drive the movable cylinder sleeve to move axially relative to the first piston and the second piston; when leaving the factory, the hydraulic cavity can also be empty, and when using it, the consumer can fill the hydraulic cavity with hydraulic oil by himself through a hydraulic pump.

[0029] Embodiment 2 of the force sensor of the present invention is as follows Figure 2 As shown: Embodiment 2 is different from Embodiment 1 in that, in this embodiment, the first piston 1 and the second piston 10 are both sleeve structures with guiding inner holes, the piston guiding section 4 is arranged on the hole wall of the corresponding guiding inner hole, the moving part 3 is a moving core whose outer periphery is guided and moved by the piston guiding section, a first piston cavity 21 is formed between one end of the moving core and the first piston, a second piston cavity 20 is formed between the other end of the moving core and the piston, a moving core channel 22 connecting the first piston cavity and the second piston cavity is provided on the moving core, the force sensor also includes a pressure sensor 14 connected to the second piston cavity, the effective pressure bearing area between one end of the moving core and the first piston cavity is equal to the effective pressure bearing area between the other end of the moving core and the second piston cavity, the moving core channel penetrates the moving core along the axial direction of the moving core, and the moving core channel is an equal-diameter channel with the same diameter along the extension direction of the channel. In this embodiment, the end faces of the moving core at both ends are planes perpendicular to the axial direction of the moving core, so the surface area of ​​each end face of the moving core is the effective pressure bearing area subjected to the liquid pressure in the corresponding piston cavity. A dynamic core flange is fixed to the outer periphery of the east core, and the driving mechanism 7 is connected to the dynamic core flange through the force sensor 6. The first sealing ring 2 is arranged between the outer periphery of the dynamic core and the first piston, and the second sealing ring 16 is arranged between the outer periphery of the dynamic core and the second piston. In other embodiments of the present invention, the dynamic core can also be a sleeve structure, in which case the inner hole of the sleeve constitutes the dynamic core channel.

[0030] The embodiment of the hydraulic bearing device is as follows Figure 1 As shown: the specific structure of the hydraulic bearing device is the same as the hydraulic bearing device in the above-mentioned force sensor embodiments, and will not be described in detail here.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A force sensor, characterized in that: The invention comprises a first piston and a second piston, wherein the first piston and the second piston have piston guide sections with the same diameter, and the piston guide sections on the first piston and the second piston are sealed and guided to move with moving parts, and the force sensor also comprises a driving mechanism for driving the moving parts to move axially relative to the first piston and the second piston along the piston guide section, and a force sensor is arranged in series on the transmission path between the driving mechanism and the moving cylinder tube, and the first piston and the second piston have the following two arrangement forms: the first one, the piston guide section is arranged on the outer peripheral surface of the first piston and the second piston, the moving part is a moving cylinder tube sleeved on the first piston and the second piston, and the first piston, the second piston and the moving cylinder tube form a hydraulic cavity, and the force sensor also comprises a pressure sensor connected to the hydraulic cavity; the second one, the first piston and the second piston have a guide inner hole, the piston guide section is arranged on the hole wall of the guide inner hole, the moving part is a moving core inserted on the first piston and the second piston, a first piston cavity is formed between one end of the moving core and the first piston, and a second piston cavity is formed between the other end of the moving core and the piston, and a moving core channel connecting the first piston cavity and the second piston cavity is provided on the moving core, and the force sensor also comprises a pressure sensor connected to the first piston cavity or the second piston cavity, The movable cylinder and the first piston are sealed by a first sealing ring, and the movable cylinder and the second piston are sealed by a second sealing ring. The materials, inner diameter and outer diameter of the first sealing ring and the second sealing ring are the same. The driving mechanism drives the movable cylinder to move axially at a uniform speed along the piston guide section. The effective pressure-bearing area between one end of the movable core and the first piston cavity is equal to the effective pressure-bearing area between the other end of the movable core and the second piston cavity. The movable core channel penetrates the movable core along the axial direction of the movable core, and the movable core channel is an equal-diameter channel with the same diameter along the extension direction of the channel.

2. A hydraulic bearing device, characterized in that: The invention comprises a first piston and a second piston, wherein the first piston and the second piston have piston guide sections with the same diameter, and the piston guide sections on the first piston and the second piston are sealed and guided to move and are equipped with moving parts, and the force sensor also comprises a driving mechanism for driving the moving parts to move axially relative to the first piston and the second piston along the piston guide sections, and a force sensor is arranged in series on the transmission path between the driving mechanism and the moving cylinder tube, and the first piston and the second piston have the following two settings: the first one, the piston guide section is arranged on the outer peripheral surface of the first piston and the second piston, and the moving part is a moving cylinder tube sleeved on the first piston and the second piston, and the first piston, the second piston and the moving cylinder tube form a hydraulic cavity; the second one, the first piston and the second piston have a guiding inner hole, the piston guide section is arranged on the hole wall of the guiding inner hole, and the moving part is a moving core inserted on the first piston and the second piston, a first piston cavity is formed between one end of the moving core and the first piston, and a second piston cavity is formed between the other end of the moving core and the piston, and a moving core channel connecting the first piston cavity and the second piston cavity is provided on the moving core, The movable cylinder and the first piston are sealed by a first sealing ring, and the movable cylinder and the second piston are sealed by a second sealing ring. The materials, inner diameter and outer diameter of the first sealing ring and the second sealing ring are the same. The driving mechanism drives the movable cylinder to move axially at a uniform speed along the piston guide section. The effective pressure-bearing area between one end of the movable core and the first piston cavity is equal to the effective pressure-bearing area between the other end of the movable core and the second piston cavity. The movable core channel penetrates the movable core along the axial direction of the movable core, and the movable core channel is an equal-diameter channel with the same diameter along the extension direction of the channel.

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