Target device for linear displacement sensor

Abstract

The utility model discloses a target device for linear displacement sensor, including inductive sheet, support, limit pin and mounting screw, the support is hollow structure and forms the buckle at lower extreme, limit pin inserts and installs in the support inside and props up buckle, inductive sheet inserts and installs in the support, the head of mounting screw forms the buckle cooperation hole that buckle of support installs into. The utility model discloses a target device adopts the support of hollow structure and the screw on the screw rod are connected through buckle, again through limit pin to buckle of support support and limit, prevent buckle rebound, avoid buckle from falling off in screw, can strengthen the bending strength of buckle again, guarantee the connection reliability of support and screw, simple structure, the number of parts is few, and the manufacturability is excellent, and moreover, the installation is simple.

Description

Technical Field

[0001] This utility model relates to sensor equipment for automotive electric power steering systems, specifically a target device for linear displacement sensors. Background Technology

[0002] In the field of electric power steering in automobiles, there are generally two methods for detecting the position of linear motion mechanisms: direct measurement and indirect measurement. Indirect measurement methods mostly use angle sensors, combined with the mechanical parameters of gear and rack transmission mechanisms or lead screw and nut transmission mechanisms, to convert angle signals into displacement signals. This method easily meets the requirements for large stroke measurement ranges, but the mechanical structure is very complex. Direct measurement methods typically use linear displacement sensors to directly detect the displacement of the linear motion mechanism. Currently, commonly used linear displacement sensors are Hall effect sensors and inductive sensors. The mechanical structures of both types of sensors are largely similar, both including a moving target and a sensing component. The smoothness of the moving target's movement and the stability of the relative position between the moving target and the sensing component are key parameters affecting the sensor's measurement accuracy.

[0003] Due to factors such as manufacturing precision, assembly errors, and part deformation under load, maintaining the stability of the moving target's posture is a key technical challenge for improving the measurement accuracy of linear displacement sensors.

[0004] The existing solutions mainly include the following:

[0005] Option 1 involves adding a sealing ring to the interface to compensate for the tolerance. The drawback of this method is that the sealing ring is a small part that is not easy to assemble.

[0006] Option 2 involves designing a grooved slide rail structure to provide precise guidance and positioning for the moving target. However, this method has the drawback of requiring high manufacturing precision for the grooved slide rail, and improper control can easily lead to jamming.

[0007] Option 3 uses a split hinge ball joint structure to compensate for errors in the rotation direction. The drawback of this method is that it cannot absorb errors caused by warping in the movement direction. Utility Model Content

[0008] The technical problem to be solved by this utility model is to provide a target device for a linear displacement sensor, which can solve the defect of poor stability of the target during movement in the existing inductive linear displacement sensor.

[0009] To solve the above problems, the present invention provides a target device for a linear displacement sensor, comprising a sensing element, a bracket, a limiting pin, and a mounting screw. The bracket has a hollow structure and a buckle is formed at its lower end. The limiting pin is inserted into the bracket and supports the buckle. The sensing element is inserted into the bracket. The head of the mounting screw has a buckle mating hole for the buckle of the bracket to be inserted.

[0010] Furthermore, the sensing element is mounted on the bracket with an interference fit.

[0011] Furthermore, the outer diameter of the limiting pin is the same as the inner diameter of the buckle.

[0012] Furthermore, the head of the mounting screw also has an internal hexagonal recess, which is located below the snap-fit ​​hole.

[0013] Furthermore, the mounting screw and the lead screw are fixedly connected by threads.

[0014] Furthermore, the bracket is made of plastic.

[0015] Furthermore, the linear displacement sensor includes a target device and a sensing component, with the target device arranged parallel to and below the sensing component.

[0016] Compared with the prior art, the technical effects that this utility model can achieve are:

[0017] 1) The target device of this utility model adopts a hollow structure bracket and a screw installed on the lead screw, which are connected by a buckle. The buckle of the bracket is supported and limited by a limiting pin, which not only prevents the buckle from springing back and avoids the buckle from falling off the screw, but also strengthens the bending strength of the buckle and ensures the reliability of the connection between the bracket and the screw.

[0018] 2) This utility model has a simple structure, few parts, excellent manufacturability, and is easy to install. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the detection principle of an inductive linear displacement sensor.

[0020] Figure 2 This is a schematic diagram of the linear displacement sensor of this utility model;

[0021] Figure 3 This is an assembly and usage diagram of the linear displacement sensor of this utility model;

[0022] Figure 4 This is a schematic diagram of the overall target device of this utility model;

[0023] Figure 5This is an exploded view of the target device of this utility model;

[0024] Figure 6 This is a partial cross-sectional view of the target device of this utility model;

[0025] Figure 7 This is a cross-sectional view of the mounting screw of this utility model;

[0026] Figure 8 This is a schematic diagram of the assembly of the mounting screw and lead screw of this utility model;

[0027] Figure 9 This is a schematic diagram of the bracket being mounted to the screw in the target device of this utility model;

[0028] Figure 10 This is an assembly diagram showing the limit pin being installed onto the bracket in the target device of this utility model;

[0029] Figure 11 This is an assembly diagram showing the sensor plate being mounted on the bracket in the target device of this utility model;

[0030] Figure 12 This is a schematic diagram of the overall assembly of the linear displacement sensor of this utility model.

[0031] The accompanying diagrams are labeled as follows:

[0032] A is the moving element; B is the substrate; B1 is the excitation coil; B2 is the receiving coil; 1 is the target device; 2 is the sensing component; 3 is the plastic encapsulated shell; 4 is the circuit board; 5 is the sensing plate; 6 is the bracket; 7 is the lead screw; 8 is the mounting screw; 9 is the housing; 10 is the limit pin; 11 is the snap-fit; 12 is the inner hole; 13 is the threaded area; 14 is the internal hexagonal recess; 15 is the snap-fit ​​mating hole. Detailed Implementation

[0033] The embodiments of this utility model are described below with reference to the accompanying drawings and specific examples. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Specific details are set forth in the following description to provide a full understanding of this utility model; however, this utility model can also be implemented or applied through other different specific embodiments, and the details in this specification can also be based on different viewpoints and applications. Those skilled in the art can make various similar extensions and substitutions without departing from the spirit of this utility model.

[0034] The target device in this embodiment is mainly applied to an inductive linear displacement sensor to detect the specific position of a linear motion mechanism during its movement. The detection principle of this inductive linear displacement sensor is as follows: Figure 1As shown, a metal moving element A is located above a substrate B, on which an excitation coil B1 and a receiving coil B2 are arranged. The excitation coil B1 can be connected to an external oscillator to generate a magnetic field. This magnetic field induces a current in the moving element A, which in turn generates a second magnetic field that is superimposed and coupled to the receiving coil B2. The receiving coil B2 generates an induced electromotive force (EMF) as the moving element A changes position. An external chip receives this EMF, processes it, and converts it into a linear output signal for the control unit.

[0035] like Figure 2 As shown, the linear displacement sensor includes a target device 1 and a sensing component 2. A circuit board 4 is disposed inside the sensing component 2, and the circuit board 4 is encapsulated in a plastic shell 3. The circuit board 4 is connected to... Figure 1 The substrate B in the target device has the same function. The target device 1 is placed parallel to the bottom of the sensing component 2. The target device 1 contains a sensing element 5, which is the... Figure 1 The metal moving element A is shown. During normal operation, the distance between the sensing element 5 and the circuit board 4 is very stable to ensure that the linear output signal has no fluctuations.

[0036] like Figure 3 As shown, the target device 1 is fixed to the lead screw 7 by mounting screws 8, and the sensing component 2 is fixed to the housing 9 by screws (not shown). When the lead screw 7 moves left and right and drives the wheel to swing through the mechanical connection structure to achieve steering, the mounting screws 8 fixed to the lead screw 7 also move left and right, thereby driving the sensing plate 5 on the target device 1 to move left and right. The sensing component 2 senses the movement of the target device 1 and transmits the position signal and speed signal of the target device 1 to the assist unit module. Finally, the assist unit provides appropriate assistance based on these signals.

[0037] In this embodiment, as Figures 4 to 7 As shown, the target device includes a sensing plate 5, a bracket 6, a limiting pin 10, and a mounting screw 8. The bracket 6 has a hollow structure with a latch 11 formed at its lower end. The limiting pin 10 is inserted into the bracket 6 and supports the latch 11 to prevent it from springing back. The sensing plate 5 is inserted into the bracket 6 with an interference fit. The head of the mounting screw 8 has a latching hole 15 for the latch 11 of the bracket 6 to be inserted. Preferably, the bracket 6 is made of plastic.

[0038] like Figure 7 As shown, the head of the mounting screw also has an internal hexagonal recess, which is located below the snap-fit ​​hole. This internal hexagonal recess facilitates the screw 8 being screwed onto the lead screw 7 using a tool.

[0039] The specific assembly process of the target device is described below.

[0040] like Figure 8 As shown, the tool is used to operate the internal hexagonal recess 14 of the mounting screw 8 so that the threaded area 13 of the mounting screw 8 is screwed into the threaded hole (not shown) of the lead screw 7.

[0041] like Figure 9 As shown, the bracket 6 is directly press-fitted into the mounting screw 8. Since the bracket 6 is a hollow structure with an inner hole 12 and is made of plastic, the clip 11 at the lower end of the bracket 6 is easily deformed under the direct pressing force, thus entering the clip mating hole 15 of the mounting screw 8.

[0042] like Figure 10 As shown, the limiting pin 10 is directly assembled into the inner hole 12 of the bracket 6 by pressing force. In the mating area between the snap fastener 11 and the snap fastener mating hole 15, the diameter of the limiting pin 10 is basically the same as the diameter of the inner hole 12. This ensures that the limiting pin 10 fills the inner hole 12 and supports the snap fastener 11, preventing the snap fastener 11 from springing back towards the center of the inner hole 12 and thus preventing it from dislodging from the snap fastener mating hole 15. At the same time, due to the supporting effect of the limiting pin 10 in the inner hole 12, the bending strength of the snap fastener 11 is strengthened, ensuring the reliability of the connection between the bracket 6 and the mounting screw 8.

[0043] Finally, as Figure 11 As shown, the sensor 5 is pressed into the bracket 6 to make them fit together with an interference fit.

[0044] Figure 12 The process of assembling the sensing component 2 into the housing 9 is described, which ultimately realizes the assembly of the linear displacement sensor.

[0045] The target device in this embodiment has a simple structure, few parts, excellent manufacturability, and is easy to install. It adopts a hollow structure bracket and a screw mounted on a lead screw, which are connected by a buckle. The buckle of the bracket is supported and limited by a limiting pin, which not only prevents the buckle from springing back and falling off the screw, but also strengthens the bending strength of the buckle and ensures the reliability of the connection between the bracket and the screw.

[0046] The present invention has been described in detail above through specific embodiments. These embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to the above-described implementation methods. Any equivalent substitutions and improvements made by those skilled in the art without departing from the principle of the present invention should be considered within the scope of the technology protected by the present invention.

Claims

1. A target device for a linear displacement sensor, characterized in that, The target device includes a sensing plate, a bracket, a limiting pin, and a mounting screw. The bracket has a hollow structure and a buckle at its lower end. The limiting pin is inserted into the bracket and supports the buckle. The sensing plate is inserted into the bracket. The head of the mounting screw has a buckle mating hole for the buckle of the bracket to be inserted.

2. The target device for a linear displacement sensor according to claim 1, characterized in that, The sensor is mounted on the bracket with an interference fit.

3. The target device for a linear displacement sensor according to claim 1, characterized in that, The outer diameter of the limiting pin is the same as the inner diameter of the buckle.

4. The target device for a linear displacement sensor according to claim 1, characterized in that, The head of the mounting screw also has an internal hexagonal recess, which is located below the snap-fit ​​hole.

5. The target device for a linear displacement sensor according to claim 1, characterized in that, The mounting screws are fixedly connected to the lead screw by threads.

6. The target device for a linear displacement sensor according to claim 1, characterized in that, The bracket is made of plastic.

7. The target device for a linear displacement sensor according to claim 1, characterized in that, The linear displacement sensor includes a target device and a sensing component, with the target device arranged parallel to and below the sensing component.

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