A pressure sensor with high overload resistance

Abstract

The present invention discloses a high overload resistant pressure sensor, comprising a base and a core body, one end of the base is provided with an inner cavity for installing the core body, the core body is located in the inner cavity, the other end of the core body is provided with a pressure-inducing hole connected to the inner cavity, the pressure-inducing hole is provided with a pressure buffer structure matching the shape of the pressure-inducing hole, the pressure buffer structure is provided with a flow channel for buffering pressure, and the two ends of the flow channel are respectively connected to the pressure-inducing hole and the inner cavity. The present invention has the advantages of simple structure, small size, easy disassembly and assembly, high reliability, good repeatability, strong high overload resistance and modular design.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of pressure sensors, and in particular to a pressure sensor resistant to high overload. Background Art

[0002] Pressure sensors are mainly used for pressure detection in various fields. In some applications, the pressure medium (such as gas or liquid) has transient overload characteristics, and the overload pressure value sometimes reaches several times the rated pressure detection value. When the overload capacity limit of the pressure sensor is exceeded, the sensor will be damaged. To avoid this situation, a throttle hole is generally added to the pressure sensor pressure inlet. Figure 1 As shown, the main components of the pressure sensor include a first base 1, a throttle screw 2 and a first core 3. During installation, the throttle screw 2 is installed in the drainage hole of the first base 1 of the pressure sensor, and the pressure medium passes through the throttle hole of the throttle screw 2 to reach the pressure-sensing part of the first core 3. The depth of the throttle hole of the throttle screw 2 generally does not exceed 80% of the depth of the pressure-inducing hole of the first base 1. The aperture of the throttle hole cannot reach the appropriate diameter calculated in theory due to processing technology and cost limitations, and this aperture is too small, not only the transient overload resistance is poor, but also the risk of clogging the pressure-inducing hole will be increased.

[0003] There are also pressure sensors that use multiple times the rated pressure detection range. This approach will also lead to reduced sensitivity of the detection output and poor measurement accuracy. Some pressure sensor structures also use spring-type pressure buffer devices to buffer the pressure pulses in the hydraulic pipeline. Due to the elastic characteristics of the spring and the limitations of the spring's geometric dimensions, the buffering pressure range is limited, and the buffering effect for high-range transient pressure overloads is limited. In addition, the structure is complex and the volume is large (it is not compatible with small-volume pressure sensors). The elastic element is not durable enough, and elastic fatigue is prone to occur after use. In addition, the accumulated wear of the moving parts makes the buffering stability of the sensor poor in long-term operation. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in view of the technical problems existing in the prior art, the present invention provides a high overload resistant pressure sensor with simple structure, small size, easy assembly and disassembly, high reliability and good repeatability.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A high overload resistant pressure sensor comprises a base and a core body, wherein one end of the base is provided with an inner cavity for mounting the core body, the core body is located in the inner cavity, the other end of the core body is provided with a pressure-inducing hole connected to the inner cavity, the pressure-inducing hole is provided with a pressure buffer structure matching the shape of the pressure-inducing hole, the pressure buffer structure is provided with a flow channel for buffering pressure, and the two ends of the flow channel are respectively connected to the pressure-inducing hole and the inner cavity.

[0007] As a further improvement of the above technical solution:

[0008] The pressure buffer structure includes a pressure buffer column and a fixing part, wherein the fixing part is connected to the pressure-inducing hole to fix the pressure buffer column in the pressure-inducing hole; the flow channel is located on the pressure buffer column, and the fixing part is provided with a channel for connecting the flow channel and the pressure-inducing hole.

[0009] The flow channel includes a first flow channel, a second flow channel and a third flow channel which are connected in sequence; the second flow channel is arranged on the outer peripheral side of the pressure buffer column; the first flow channel is located inside the pressure buffer column, one end of which is connected to the pressure-inducing hole, and the other end of which is connected to one end of the second flow channel; the third flow channel is located inside the pressure buffer column, one end of which is connected to the other end of the second flow channel, and the other end of which is connected to the inner cavity.

[0010] The first flow channel and the third flow channel are both in a straight line shape.

[0011] The second flow channel is S-shaped or spiral-shaped.

[0012] One end of the fixing member in contact with the pressure buffer column is provided with a pressure-inducing cavity for connecting the hole and the first flow channel.

[0013] The fixing member is a fixing screw, which is threadedly connected to the pressure-inducing hole.

[0014] The pressure buffer column and the fixing piece are an integrated structure.

[0015] Compared with the prior art, the advantages of the present invention are:

[0016] The present invention is based on the corresponding fluid mechanics principle (the longer the flow channel, the stronger the pressure suppression capability), and adopts a flow channel of appropriate length to buffer the overload pressure. Specifically, a pressure buffer structure is added in the pressure inlet hole, and a flow channel that meets the length requirement is added on the pressure buffer structure, thereby suppressing the transient overload pressure and protecting the core from damage. The overall structure is simple and small in size, the pressure buffer structure will not be damaged by the transient overload pressure, it has high reliability and good repeatability, and the theoretical ability to resist transient overload pressure will not change.

[0017] The pressure buffer structure of the present invention includes a pressure buffer column and a fixing part, which is connected to the pressure-inducing hole to fix the pressure buffer column in the pressure-inducing hole, and is easy to disassemble and assemble; or the pressure buffer column and the fixing part can also be an integrated structure; the overall pressure buffer structure can be replaced as an independently designed component, thereby improving the dynamic response performance of sensors with different overload pressure requirements.

[0018] The present invention adopts an S-shaped flow channel arranged on the outer peripheral side of the pressure buffer column, so as to extend the length of the flow channel as much as possible under the condition of a certain length of the pressure buffer column, thereby achieving a higher overload resistance; relatively speaking, the length of the pressure buffer column can also be reduced as much as possible, so that the pressure buffer structure can be suitable for use in a small-volume pressure-inducing hole.

[0019] The present invention can adjust the dynamic performance of the pressure sensor for transient high overload by adjusting the design parameters such as the length of the pressure buffer column, the number and geometric dimensions of the S-shaped flow channels on the surface. Of course, in other embodiments, the second flow channel can also be in other shapes such as a spiral shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional view of a pressure sensor in the prior art.

[0021] Figure 2 It is a cross-sectional view of an embodiment of a pressure sensor of the present invention.

[0022] Figure 3 It is a cross-sectional view of a pressure buffer column in an embodiment of the present invention.

[0023] Figure 4 It is a stereoscopic view of a pressure buffer column in an embodiment of the present invention.

[0024] The numbers in the figure indicate: 1. first base; 2. throttle screw; 3. first core; 4. base; 5. core; 6. inner cavity; 7. pressure-inducing hole; 8. pressure buffer structure; 81. pressure buffer column; 811. first flow channel; 812. second flow channel; 813. third flow channel; 82. fixing part; 821. hole; 822. pressure-inducing cavity. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] like Figure 2As shown, the high overload resistant pressure sensor of this embodiment includes a base 4 and a core 5. One end of the base 4 is provided with an inner cavity 6 for installing the core 5. The core 5 is located in the inner cavity 6. The other end of the core 5 is provided with a pressure-inducing hole 7 connected to the inner cavity 6. The pressure-inducing hole 7 is provided with a pressure buffer structure 8 matching the shape of the pressure-inducing hole 7. The pressure buffer structure 8 is provided with a flow channel for buffering pressure. The two ends of the flow channel are respectively connected to the pressure-inducing hole 7 and the inner cavity 6. When a high transient overload occurs in the pressure medium (such as a liquid medium or a gas medium, etc.), the flow channel on the pressure buffer structure 8 will have the ability to suppress the transient overload pressure, thereby protecting the core 5 from damage.

[0027] According to the principles of fluid mechanics, under the same flow channel diameter, increasing the flow channel length can enhance the ability to suppress transient overload pressure when the fluid medium passes through the flow channel. The present invention is based on the above principle, and a pressure buffer structure 8 is added in the pressure inlet hole 7, and a flow channel that meets the length requirements is added on the pressure buffer structure 8, so as to suppress transient overload pressure and protect the core 5 from damage; the overall structure is simple and small in size, and is suitable for micro pressure sensors; the above pressure buffer structure 8 (i.e., the flow channel on the column) will not be damaged by transient overload pressure, and its reliability is high, the theoretical ability to resist transient overload pressure will not change, and the repeated stability is good.

[0028] Specifically, the pressure buffer structure 8 includes a pressure buffer column 81 and a fixing member 82. The fixing member 82 is connected to the pressure-inducing hole 7 to fix the pressure buffer column 81 in the pressure-inducing hole 7. Figure 2 As shown, the fixing member 82 is a fixing screw, which is threadedly connected to the pressure-inducing hole 7 to clamp the pressure buffer column 81 in the pressure-inducing hole 7, and is easy to disassemble and assemble. In addition, the pressure buffer column 81 and the fixing member 82 can also be an integrated structure. The shape of the pressure buffer column 81 matches the pressure-inducing hole 7. The pressure-inducing hole 7 in the conventional structure is a round hole, so the pressure buffer column 81 is columnar. The flow channel is located on the pressure buffer column 81, and a hole 821 for connecting the flow channel and the pressure-inducing hole 7 is provided on the fixing screw, wherein the size of the hole 821 is set according to actual needs; in some cases, this hole 821 can also be set as a throttling hole to further play an overload resistance capability. The above-mentioned pressure buffer structure 8 can be replaced as an independently designed component, which improves the dynamic response performance of sensors with different overload pressure requirements, and is easy to disassemble and assemble.

[0029] like Figure 3 and Figure 4As shown, in this embodiment, the flow channel includes a first flow channel 811, a second flow channel 812 and a third flow channel 813 which are connected in sequence; the second flow channel 812 is arranged on the outer peripheral side of the pressure buffer column 81; the first flow channel 811 is located inside the pressure buffer column 81, one end of which is connected to the pressure-inducing hole 7, and the other end is connected to one end of the second flow channel 812; the third flow channel 813 is located inside the pressure buffer column 81, one end of which is connected to the other end of the second flow channel 812, and the other end is connected to the inner cavity 6. The first flow channel 811 and the third flow channel 813 are both straight; the second flow channel 812 is S-shaped, which can ensure that the flow channel distance is long and has a good resistance to overload pressure, and the S shape is also easy to process.

[0030] The present invention adopts an S-shaped flow channel arranged on the outer peripheral side of the pressure buffer column 81, and the length of the flow channel is extended as much as possible when the length of the pressure buffer column 81 is constant, so as to have a higher overload resistance; relatively speaking, the length of the pressure buffer column 81 can also be reduced as much as possible, so that the pressure buffer structure 8 can be suitable for a small-volume pressure-inducing hole 7. In other embodiments, the second flow channel 812 can also be a spiral or other shape. Of course, the size of the above-mentioned flow channel is selected according to the actual situation. The smaller the size, the better when it is not blocked, so as to minimize the volume.

[0031] The present invention can adjust the dynamic performance of the pressure sensor under transient high overload by adjusting design parameters such as the length of the pressure buffer column 81, the number and geometric dimensions of the S-shaped flow channels on the surface, etc.

[0032] In this embodiment, the end of the fixing screw that contacts the pressure buffer column 81 is provided with a pressure-inducing cavity 822 that connects the hole 821 and the first flow channel 811 , which is used to guide the pressure through the hole 821 to the inlet of the first flow channel 811 of the pressure buffer column 81 .

[0033] When the pressure sensor is working normally, the pressure medium enters the hole 821 of the fixing screw through the pressure-introducing hole 7, and then flows to the first flow channel 811 through the pressure-introducing cavity 822, and then flows into the inner cavity 6 after passing through the second flow channel 812 and the third flow channel 813 in sequence, and reaches the pressure-sensing part of the core 5. In the case of a high transient overload (for example, within the transient overload pressure range of 2 times the range of 10 milliseconds), the overload pressure will be suppressed in the flow channel formed by the first flow channel 811, the second flow channel 812 and the third flow channel 813, so that the pressure reaching the core 5 is within the rated pressure range of the core 5, ensuring that it is not damaged.

[0034] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A high overload resistant pressure sensor, comprising a base (4) and a core (5), wherein one end of the base (4) is provided with an inner cavity (6) for mounting the core (5), the core (5) is located in the inner cavity (6), and the other end of the core (5) is provided with a pressure-inducing hole (7) connected to the inner cavity (6), characterized in that: A pressure buffer structure (8) having a shape matching that of the pressure-inducing hole (7) is provided in the pressure-inducing hole (7), and a flow channel for buffering pressure is provided on the pressure-inducing structure (8), wherein two ends of the flow channel are respectively connected to the pressure-inducing hole (7) and the inner cavity (6); The pressure buffer structure (8) comprises a pressure buffer column (81) and a fixing member (82), wherein the fixing member (82) is connected to the pressure induction hole (7) to fix the pressure buffer column (81) in the pressure induction hole (7); the flow channel is located on the pressure buffer column (81), and the fixing member (82) is provided with a hole (821) for connecting the flow channel and the pressure induction hole (7); The flow channel comprises a first flow channel (811), a second flow channel (812) and a third flow channel (813) which are connected in sequence; the second flow channel (812) is arranged on the outer peripheral side of the pressure buffer column (81); the first flow channel (811) is located inside the pressure buffer column (81), one end of which is connected to the pressure inlet hole (7), and the other end of which is connected to one end of the second flow channel (812); the third flow channel (813) is located inside the pressure buffer column (81), one end of which is connected to the other end of the second flow channel (812), and the other end of which is connected to the inner cavity (6); The second flow channel (812) is S-shaped or spiral-shaped; The end of the fixing member (82) in contact with the pressure buffer column (81) is provided with a pressure-inducing cavity (822) for connecting the hole (821) with the first flow channel (811).

2. The high overload resistant pressure sensor according to claim 1, characterized in that: The first flow channel (811) and the third flow channel (813) are both in a straight line shape.

3. The high overload resistant pressure sensor according to claim 1 or 2, characterized in that: The fixing member (82) is a fixing screw, which is threadedly connected to the pressure-inducing hole (7).

4. The high overload resistant pressure sensor according to claim 1 or 2, characterized in that: The pressure buffer column (81) and the fixing member (82) are an integrated structure.

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