Dimension measuring device

Abstract

The utility model discloses a size measuring device which comprises a meter type measuring instrument which is provided with a measuring rod and a transmission mechanism capable of converting linear motion of the measuring rod into rotary motion of a pointer, and further comprises a measuring head fixedly connected with one end, far away from a dial plate of the measuring instrument, of the measuring rod. The measuring head comprises a fixed part fixedly connected with the measuring rod and a plurality of cantilevers uniformly distributed around the axis of the measuring rod; and all the cantilevers are coplanar on a plane which meets a vertical condition with the axis of the measuring rod. The cantilever is movably connected with the fixing part and can change positions between at least two different stations, and when the station where the cantilever is located changes, the size of the measuring head in the radial direction of the measuring rod changes. The dimension measuring device provided by the utility model can more accurately measure the distance between the end faces of the valve rod and the sleeve of the urea nozzle in a combined state.

Description

Technical Field

[0001] The present application relates to the technical field of dimension measurement, and in particular to a dimension measurement device. Background Art

[0002] The urea nozzle in the automobile exhaust treatment system is used to spray the urea delivered by the urea pump into the mixer after atomization, so that the urea and the exhaust gas are fully mixed to reduce the concentration of nitrogen oxides in the exhaust gas. In the production process of urea nozzles, if the good air gap consistency cannot be guaranteed, the product's injection accuracy, spray characteristics and other performance will be poor. The air gap of the urea nozzle refers to the working stroke of its valve stem, that is, the distance the valve stem moves from the non-injection sealing state to the highest point after the solenoid valve is powered.

[0003] In order to ensure good air gap consistency, workers need to accurately measure the relevant dimensions, for example, they need to measure the distance between the end faces of the valve stem and the sleeve when they are combined, close to the iron core, so as to select the iron core of the appropriate size. However, the accuracy of measuring the end face distance of the valve stem and the sleeve when they are combined using current tools is poor. Therefore, how to more accurately measure the above end face distance has become a technical problem that needs to be solved urgently by technicians in this field. Utility Model Content

[0004] In view of this, the purpose of the present application is to provide a dimension measuring device so as to more accurately measure the end surface distance between the valve stem and the sleeve of the urea nozzle in the assembled state.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] A dimension measuring device includes a dial-type measuring instrument, the measuring instrument having a measuring rod and a transmission mechanism capable of converting the linear motion of the measuring rod into the rotational motion of a pointer, and also including a measuring head fixedly connected to an end of the measuring rod away from the dial of the measuring instrument, the measuring head including:

[0007] A fixing part, fixedly connected to the measuring rod;

[0008] A plurality of cantilevers are evenly distributed around the axis of the measuring rod, and all the cantilevers are coplanar with a plane that meets the perpendicular condition to the axis of the measuring rod;

[0009] The cantilever is movably connected to the fixing portion and can be changed between at least two different positions. When the position of the cantilever changes, the radial dimension of the measuring head in the measuring rod changes.

[0010] Optionally, in the above-mentioned dimension measuring device, the cantilever is hinged to the fixing part, and a hinge axis between the cantilever and the fixing part and an axis line of the measuring rod meet a parallel condition.

[0011] Optionally, in the above-mentioned dimension measuring device, the cantilever is configured as an arc rod, and one end of the arc rod is hinged to the fixing portion.

[0012] Optionally, in the above-mentioned dimension measuring device, the fixing portion includes a plurality of straight rods radially distributed with the axis of the measuring rod as the center, and one end of the straight rod away from the center is hinged to the cantilever.

[0013] Optionally, in the above-mentioned dimension measuring device, the cantilever and the fixing portion have a height difference in the axial direction of the measuring rod, and the cantilever is farther from the dial of the measuring instrument than the fixing portion in the axial direction of the measuring rod.

[0014] Optionally, in the above-mentioned size measuring device, a bracket is further included, and the bracket includes:

[0015] A column, wherein the column is provided with a guide rail extending along the axial direction of the column;

[0016] A support arm is capable of moving along the guide rail and being fixed at any position of the guide rail, and a connecting portion for fixedly connecting with the measuring instrument is provided at one end of the support arm away from the column.

[0017] Optionally, in the above-mentioned dimension measuring device, the connecting portion is configured as a slot for snapping into the shaft barrel portion of the measuring instrument.

[0018] Optionally, the dimension measuring device further comprises a fixture for fixing the workpiece to be measured, wherein the fixture comprises a first clamping block and a second clamping block capable of relative movement along a first direction, and the first direction is perpendicular to the axial direction of the column.

[0019] Optionally, in the above-mentioned dimension measuring device, the first clamping block and the second clamping block are provided with V-shaped grooves opposite to each other, and the groove walls of the V-shaped grooves are used to abut against the outer surface of the workpiece to be measured.

[0020] Optionally, in the above-mentioned dimension measuring device, the clamp includes a base, the first clamp block is fixedly connected to the base, the second clamp block is slidably connected to the base, and a traction rod passing through a raised portion of the base is connected to the side of the second clamp block away from the first clamp block, and a spring is sleeved on the traction rod, and two ends of the spring respectively abut against the second clamp block and the raised portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0022] Figure 1 It is a structural schematic diagram of the urea nozzle;

[0023] Figure 2 It is a schematic diagram of the combined state after the valve stem 03 is assembled to the sleeve 04;

[0024] Figure 3 The core 02 is assembled to Figure 2 A schematic diagram of the structure shown;

[0025] Figure 4 is a schematic diagram of the use state of the size measuring device provided in an embodiment of the present application;

[0026] Figure 5 yes Figure 4 a front view of the structure shown;

[0027] Figure 6 yes Figure 5 A top view of

[0028] Figure 7 yes Figure 5 Right view of;

[0029] Figure 8 yes Figure 5 Left view of .

[0030] The markings in the figure are:

[0031] 01, electromagnet; 02, iron core; 03, valve stem; 04, casing;

[0032] 1. Measuring instrument; 11. Measuring rod; 21. Fixing part; 22. Cantilever; 31. First clamping block; 32. Second clamping block; 33. Base; 331. Raised part; 34. Drawbar; 4. Spring; 51. Support plate; 52. Support arm; 53. Column. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] See also Figure 1 The urea nozzle includes an electromagnet 01, an iron core 02, a valve stem 03 and a sleeve 04. The sleeve 04 is relatively fixed to the electromagnet 01, and a valve seat with a spray hole is provided at the lower end of the sleeve 04. The valve stem 03 is located in the sleeve 04 and can move up and down within the movement stroke. A valve ball is provided at the lower end of the valve stem 03 to seal the spray hole of the valve seat so that the urea nozzle can spray or stop spraying. The iron core 02 is located in the electromagnet 01 and is relatively fixed to the sleeve 04. Its function is to enhance the magnetic force generated by the electromagnetic coil, strengthen the electromagnetic force attraction to the valve stem 03, and at the same time serve as a urea flow channel.

[0035] See also Figure 2 and Figure 3 , when the valve stem 03 and the sleeve 04 are combined, the distance between the valve stem 03 and the end face of the sleeve 04 close to the iron core 02 is the length X, and when the iron core 02 and the sleeve 04 are combined, the part of the iron core 02 extending into the sleeve 04 is the length Y. The difference between the length X and the length Y is the working stroke of the valve stem 03, that is, the air gap Z of the urea nozzle. In the production and manufacturing process of the urea nozzle, the value of the length Y can be obtained when the offline inspection is completed through machining and other processes. It can be divided into multiple groups to be selected according to the air gap tolerance. After the length X is measured, the iron core 02 of the appropriate group is selected according to the set maximum deviation of the air gap Z, so as to ensure that the air gap consistency meets the design requirements.

[0036] like Figure 2 As shown, the measured length X can be obtained by measuring the total length X1 of the sleeve 04 and the distance X2 from the upper end of the valve stem 03 to the lower end of the sleeve 04, but this measurement method has the problem of difficulty in measuring the distance X2. Another method of measuring the length X is to use a universal length measuring instrument 1 (such as a dial indicator) to directly measure the length of the sleeve 04. Figure 2 The length X in the measurement is measured. This method has a smaller measurement deviation and is easier to implement. However, since the valve stem 03 needs to be able to move up and down in the sleeve 04, in order to prevent the valve stem 03 from being worn, the head of the valve stem 03 (i.e., the upper part of the valve stem 03) and the inner wall of the sleeve 04 are designed to be clearance-matched. Since the lower part of the valve stem 03 is in surface contact with the valve seat at the sealing cone surface, the valve stem 03 in the free state is in a free deflected position due to gravity and the deflection direction is uncertain. Therefore, when the probe of the universal length measuring instrument 1 contacts the head of the valve stem 03 from top to bottom, the valve stem 03 will tilt toward the force contact point, resulting in a large deviation in the measured value of the length X.

[0037] See also Figures 4 to 8 The present invention provides a dimension measuring device, which can be used to directly measure Figure 2The length X in the measurement value can be effectively improved. The dimension measuring device includes a dial measuring instrument 1, which has a measuring rod 11 and a transmission mechanism that can convert the linear motion of the measuring rod 11 into the rotational motion of the pointer. The structure and principle thereof can refer to the dial indicator in the prior art. The dimension measuring device also includes a measuring head fixedly connected to the end of the measuring rod 11 away from the dial of the measuring instrument 1, and the measuring head includes a fixing portion 21 fixedly connected to the measuring rod 11 and a plurality of cantilevers 22 evenly distributed around the axis of the measuring rod 11, and all the cantilevers 22 are coplanar with a plane that meets the vertical condition with the axis of the measuring rod 11. The cantilever 22 is movably connected to the fixing portion 21 and can change position between at least two different workstations. When the workstation where the cantilever 22 is located changes, the radial dimension of the measuring head in the measuring rod 11 changes.

[0038] Since the radial size of the measuring head in the measuring rod 11 changes when the position of the cantilever 22 changes, the size occupied by the measuring head can be increased or decreased by adjusting the cantilever 22, such as Figure 2 and Figure 4 As shown, when the dimension measuring device of the present application is used to measure the length X, the cantilever 22 is first adjusted so that the dimension occupied by the measuring head is smaller than the inner diameter of the head of the sleeve 04, but larger than the inner diameter of the head of the valve stem 03, and then the measuring head is brought into contact with the head of the valve stem 03 from top to bottom. At this time, the pointer of the measuring instrument 1 points to the 0 scale on the dial, and then the measuring instrument 1 and the sleeve 04 are kept fixed, and the measuring head is moved from bottom to top to the top of the sleeve 04, and the cantilever 22 is adjusted so that the dimension occupied by the measuring head is larger than the inner diameter of the head of the sleeve 04, and finally the measuring head is placed on the upper end face of the sleeve 04, and the measured value of the length X is read from the dial of the measuring instrument 1. Since there are multiple cantilever arms 22 and they are evenly distributed around the axis of the measuring rod 11, when the measuring head contacts the head of the valve stem 03 from top to bottom, the valve stem 03 will not tilt relative to the sleeve 04, that is, the valve stem 03 will remain coaxial with the sleeve 04 under the contact of multiple evenly distributed cantilever arms 22, so the measured value of the length X is more accurate.

[0039] like Figure 4 As shown in FIG. 1 , in a preferred embodiment, the cantilever 22 is hinged to the fixing portion 21, and the hinge axis of the cantilever 22 and the fixing portion 21 is parallel to the axis of the measuring rod 11. When the size occupied by the measuring head is to be increased, the cantilever 22 is rotated outward to extend the cantilever 22; conversely, when the size occupied by the measuring head is to be reduced, the cantilever 22 is rotated inward to close the cantilever 22. The number of cantilever 22 can be as follows: Figure 4 The setting shown is four, but it can also be set to other values, such as two, three or five.

[0040] Further preferably, the cantilever 22 is configured as an arc rod, one end of which is hinged to the fixing portion 21. Figure 4As shown, by adjusting the position of the cantilever 22, all the cantilevers 22 can be located on the same circle. When the measuring head enters the sleeve 04 from top to bottom, the circle formed by the cantilever 22 contacts the head of the valve stem 03, thereby obtaining a larger contact area, which is more conducive to preventing the valve stem 03 from tilting. Of course, in other embodiments, the cantilever 22 can also be set to other shapes, such as a straight rod shape.

[0041] like Figure 4 As shown, in this embodiment, the fixing part 21 includes a plurality of straight rods radially distributed with the axis of the measuring rod 11 as the center, and the ends of the straight rods away from the center are hinged to the cantilever 22. In this structure, the number of straight rods is equal to the number of cantilever arms 22, and the cantilever arms 22 are connected to the straight rods one by one. Of course, in other embodiments, the fixing part 21 can also be set as other structural forms, for example, the fixing part 21 is set as a disc coaxial with the measuring rod 11.

[0042] like Figure 4 As shown, in this embodiment, the cantilever 22 and the fixing part 21 have a height difference in the axial direction of the measuring rod 11, and the cantilever 22 is farther from the dial of the measuring instrument 1 than the fixing part 21 in the axial direction of the measuring rod 11. In this way, whether the measuring head contacts the upper end surface of the valve stem 03 or the upper end surface of the sleeve 04, it contacts through the lower surface of the cantilever 22. Of course, in other embodiments, the lower surface of the cantilever 22 can also be set to be always flush with the lower surface of the fixing part 21.

[0043] In addition, the movable connection between the cantilever 22 and the fixed part 21 can be set in other forms, for example, the cantilever 22 is set to be slidably connected with the fixed part 21, and preferably, the cantilever 22 slides relative to the fixed part 21 along a straight line perpendicularly intersecting the axis of the measuring rod 11. For another example, the cantilever 22 is set to be hinged with the fixed part 21, and the hinge axis and the axis of the measuring rod 11 meet the vertical condition. When the size occupied by the measuring head is to be increased, the cantilever 22 is rotated outward, so that the cantilever 22 is placed from top to bottom to be flush with the lower surface of the fixed part 21 and locked; conversely, when the size occupied by the measuring head is to be reduced, the lock is released and the cantilever 22 is rotated inward, so that the cantilever 22 is folded from bottom to top above the fixed part 21.

[0044] See also Figures 4 to 8In a preferred embodiment, the dimension measuring device further comprises a bracket, which comprises a column 53 and a support arm 52, wherein the column 53 is provided with a guide rail extending along the axial direction of the column 53, the support arm 52 can move along the guide rail and can be fixed at any position of the guide rail, and the end of the support arm 52 away from the column 53 is provided with a connection portion for fixed connection with the measuring instrument 1. The function of the bracket is to adjust the position of the measuring instrument 1 and fix the position of the measuring instrument 1 after the measuring head contacts the upper end of the valve stem 03. When in use, the measuring instrument 1 is installed at the connection portion of the support arm 52, the measuring rod 11 and the column 53 are parallel to each other, and the position of the measuring instrument 1 can be adjusted by sliding the support arm 52 along the guide rail of the column 53. For example, the measuring instrument 1 can be moved from top to bottom so that the head of the measuring head enters the sleeve 04 from top to bottom and contacts the upper end of the valve stem 03.

[0045] Specifically, there are many options for the structural form of the connecting portion. For example, the connecting portion can be set as a slot for clamping the rod barrel portion of the measuring instrument 1. It should be noted that the measuring rod 11 is inserted into the rod barrel portion of the measuring instrument 1, so the clamping and fixing of the rod barrel portion in the slot of the support arm 52 will not affect the movement of the measuring rod 11. Setting the connecting portion as a slot can make it easier to install the measuring instrument 1 on the support arm 52 and remove the measuring instrument 1 from the support arm 52, so this application uses it as a preferred embodiment. Of course, the connecting portion can also be set as other structural forms, such as a movable clamp structure. In order to improve the stability of the bracket, a support plate 51 fixedly connected to the column 53 can be set below the column 53, and the support plate 51 can increase the support area, thereby improving stability. Of course, the column 53 can also be directly fixed on the workbench.

[0046] In order to facilitate the measurement of the workpiece to be measured, in a preferred embodiment, the dimension measuring device also includes a fixture for fixing the workpiece to be measured, and the fixture includes a first clamp block 31 and a second clamp block 32 that can move relative to each other in a first direction, and the first direction satisfies the vertical condition with the axial direction of the column 53. Further preferably, the first clamp block 31 and the second clamp block 32 are relatively provided with V-shaped grooves, that is, a V-shaped groove is provided on the side of the first clamp block 31 close to the second clamp block 32, and a V-shaped groove is also provided on the side of the second clamp block 32 close to the first clamp block 31, and the notches of the two V-shaped grooves are opposite, and when the first clamp block 31 and the second clamp block 32 are close to each other to clamp the workpiece to be measured, the groove wall of the V-shaped groove abuts against the outer surface of the workpiece to be measured. The V-shaped groove can achieve rapid positioning and improve the clamping effect of the workpiece, so the present application takes the clamp of the above structure as a preferred embodiment.

[0047] like Figure 4As shown, in this embodiment, the clamp includes a base 33, a first clamp block 31 is fixedly connected to the base 33, a second clamp block 32 is slidably connected to the base 33, and a traction rod 34 is connected to the side of the second clamp block 32 away from the first clamp block 31, which is penetrated by the protrusion 331 of the base 33, and a spring 4 is sleeved on the traction rod 34, and the two ends of the spring 4 are respectively against the second clamp block 32 and the protrusion 331. The spring 4 is always in a compressed state. After the workpiece to be measured is taken, the traction rod 34 is first moved away from the first clamp block 31 to pull the second clamp block 32 and the first clamp block 31 apart by a certain distance, and then the workpiece to be measured is placed between the second clamp block 32 and the first clamp block 31, and finally the traction rod 34 is released, and the second clamp block 32 presses the workpiece to be measured under the action of the spring 4 to achieve positioning and clamping.

[0048] In this specification, each part of the structure is described in a progressive manner, and the structure of each part focuses on the differences from the existing structure. The overall and partial structures of the dimension measuring device can be obtained by combining the structures of the above multiple parts.

[0049] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dimension measuring device, comprising a dial measuring instrument, the measuring instrument having a measuring rod and a transmission mechanism capable of converting the linear motion of the measuring rod into the rotational motion of a pointer, characterized in that: It also includes a measuring head fixedly connected to one end of the measuring rod away from the dial of the measuring instrument, and the measuring head includes: A fixing part, fixedly connected to the measuring rod; A plurality of cantilevers are evenly distributed around the axis of the measuring rod, and all the cantilevers are coplanar with a plane that meets the perpendicular condition to the axis of the measuring rod; The cantilever is movably connected to the fixing portion and can be changed between at least two different positions. When the position of the cantilever changes, the radial dimension of the measuring head in the measuring rod changes.

2. The dimension measuring device according to claim 1, characterized in that: The cantilever is hinged to the fixing portion, and a hinge axis between the cantilever and the fixing portion and an axis line of the measuring rod meet a parallel condition.

3. The dimension measuring device according to claim 2, characterized in that: The cantilever is configured as an arc rod, one end of which is hinged to the fixing portion.

4. The dimension measuring device according to claim 2, characterized in that: The fixing part comprises a plurality of straight rods which are radially distributed with the axis of the measuring rod as the center, and one end of the straight rod away from the center is hinged to the cantilever.

5. The dimension measuring device according to claim 2, characterized in that: The cantilever and the fixing portion have a height difference in the axial direction of the measuring rod, and the cantilever is farther from the dial of the measuring instrument than the fixing portion in the axial direction of the measuring rod.

6. The dimension measuring device according to any one of claims 1 to 5, characterized in that: Also included is a bracket, the bracket comprising: A column, wherein the column is provided with a guide rail extending along the axial direction of the column; A support arm is capable of moving along the guide rail and being fixed at any position of the guide rail, and a connecting portion for fixedly connecting with the measuring instrument is provided at one end of the support arm away from the column.

7. The dimension measuring device according to claim 6, characterized in that: The connecting portion is configured as a slot for snapping into the rod barrel portion of the measuring instrument.

8. The dimension measuring device according to claim 6, characterized in that: It also includes a fixture for fixing the workpiece to be measured, the fixture includes a first clamping block and a second clamping block that can move relative to each other along a first direction, and the first direction meets the axial direction of the column to meet the vertical condition.

9. The dimension measuring device according to claim 8, characterized in that: The first clamping block and the second clamping block are oppositely provided with V-shaped grooves, and the groove walls of the V-shaped grooves are used to abut against the outer surface of the workpiece to be measured.

10. The dimension measuring device according to claim 8, characterized in that: The clamp includes a base, the first clamping block is fixedly connected to the base, the second clamping block is slidably connected to the base, and a traction rod passing through a raised portion of the base is connected to the side of the second clamping block away from the first clamping block, and a spring is sleeved on the traction rod, and two ends of the spring are respectively against the second clamping block and the raised portion.

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