Mold assembly and force measuring device

Abstract

The utility model relates to a mold assembly and a force measuring device. The mold assembly is used in an integral forming process to produce a force measuring device. The force measuring device comprises a main body and one or more force measuring sensors. The mold assembly comprises a male mold and a female mold. The male die comprises one or more male die cavity walls, each male die cavity wall is provided with one or more limiting parts, and each limiting part is used for placing a corresponding force transducer. The female mold includes one or more female mold cavity walls. When the female mold and the male mold are closed, each of the one or more female mold cavity walls is matched with a corresponding male mold cavity wall of the one or more male mold cavity walls to form one or more main body cavities, and each main body cavity is used for accommodating a material for forming a main body of the force measuring device. The force measuring sensor and the body in the force measuring device produced by using the die assembly disclosed by the utility model are fixed more firmly and are not easy to fall off.

Description

TECHNICAL FIELD

[0001] The utility model relates to pressure measuring device field especially relates to the mould for producing pressure measuring device. BACKGROUND

[0002] Strain gauge as a common force sensor, it can be widely used in engineering structure, medical treatment, industry and many fields. For example, strain gauge can be fixed to the measured part (for example, plastic parts, metal parts, or engineering concrete parts) to form a pressure measuring device (also known as force measuring device). The strain gauge on the force measuring device can measure the force on the force measuring device. The measurement accuracy of the strain gauge is directly related to its fixing method and fixing position on the force measuring device. At present, the main way to fix the strain gauge on the force measuring device is to use adhesive, that is, to use adhesive to fix the strain gauge on the measured part to form the force measuring device. However, this fixing method has many shortcomings.

[0003] Firstly, in the process of fixing the strain gauge by using adhesive, the local area on the measured part for fixing the strain gauge needs to be surface polished before gluing, so that the strain gauge can be stably pasted on the measured part. In addition, in order to ensure the accuracy of the fixing position of the strain gauge on the measured part, a measuring tool such as a caliper is used to manually draw a line and mark the fixing position before gluing. These operation requirements increase the operation complexity and operation cost of the adhesive fixing method.

[0004] Secondly, the adhesive used in the gluing process usually includes 502 quick-drying glue, epoxy resin glue, AB glue, polyurethane glue, etc. However, 502 quick-drying glue is prone to hardening after gluing, which may affect the measurement accuracy; and the curing conditions of other glues are relatively harsh, which requires corresponding fixtures to be designed to control time, temperature, pressure, etc., which not only leads to a long curing cycle, but also increases the cost.

[0005] Thirdly, when the strain gauge is fixed to the plastic part by gluing, since the plastic part is formed by injection molding process, there will be oily substances such as release agent on its surface, which will affect the reliability of the strain gauge adhesion, thereby affecting the measurement accuracy. CONTENT OF THE UTILITY MODEL

[0006] The technical solution provided by the utility model aims to solve one or more of the above-mentioned shortcomings in the prior art.

[0007] In one aspect of the present disclosure, a mold assembly for use in an integral molding process to produce a force measurement device including a body and one or more force sensors is provided, the mold assembly comprising: a male mold including one or more male mold cavity walls, each male mold cavity wall having one or more retaining portions thereon, each retaining portion for placing a respective force sensor; a female mold including one or more female mold cavity walls, wherein when the female mold is mated with the male mold, each of the one or more female mold cavity walls cooperates with a respective one of the one or more male mold cavity walls to form one or more body cavities, each body cavity for receiving material for forming a body of a force measurement device.

[0008] In at least one embodiment of one aspect of the present disclosure, at least one of the one or more retaining portions is a retaining slot for placing a respective force sensor therein.

[0009] In at least one embodiment of one aspect of the present disclosure, the retaining slot is shaped to conform to an outer profile of the respective force sensor to prevent movement of the respective force sensor within the retaining slot.

[0010] In at least one embodiment of one aspect of the present disclosure, at least one of the one or more retaining portions includes a retaining protrusion for cooperating with a retaining recess on a respective force sensor.

[0011] In at least one embodiment of one aspect of the present disclosure, the retaining protrusion is a retaining post and the retaining recess is a retaining hole.

[0012] In at least one embodiment of one aspect of the present disclosure, each of the at least one retaining portions includes at least two of the retaining posts, each retaining post for cooperating with a respective retaining hole on the respective force sensor.

[0013] In at least one embodiment of one aspect of the present disclosure, the female mold further includes a feed port in communication with the one or more body cavities when the female mold is mated with the male mold.

[0014] In at least one embodiment of one aspect of the present disclosure, the male mold includes a mounting portion and the female mold includes a mounting cooperating portion that cooperates with the mounting portion of the male mold when the female mold is mated with the male mold.

[0015] In another aspect of the present disclosure, there is provided a force measuring device produced using the mold assembly of any of the preceding paragraphs, and comprising: a body; and one or more force sensors fixed to the body.

[0016] In at least one embodiment of another aspect of the present disclosure, each of the one or more force sensors is a strain gauge.

[0017] Compared with the prior art, the present utility model can have one or more of the following advantages:

[0018] (1) The mold assembly of the present utility model has a limiting portion for placing a force sensor designed on the male mold and is used in an integrated molding process to produce a force measuring device, which, on the one hand, allows the force sensor to be fixed to the body of the force measuring device during the integrated molding process of the body, thereby simplifying the production process of the force measuring device and enabling mass production of the force measuring device, which in turn can shorten the production cycle and reduce the production cost, and on the other hand, the fixation between the force sensor and the body after integrated molding is more secure and less likely to fall off, thereby improving the measurement accuracy of the force measuring device.

[0019] (2) By designing the limiting portion as a limiting groove and further designing the shape of the limiting groove to be compatible with the outer contour of the force sensor, the force sensor located in the limiting groove can be prevented from being displaced by the impact of the material during the feeding process, thereby improving the accuracy of the fixed position of the force sensor on the force measuring device and further improving the measurement accuracy of the force measuring device.

[0020] (3) The position of the limiting portion for placing the force sensor on the male mold of the mold assembly is fixed, so the fixed position of the force sensor has little difference between each force measuring device produced. BRIEF DESCRIPTION OF DRAWINGS

[0021] To further clarify the above and other advantages and features of the embodiments of the present utility model, more particular description of the embodiments of the present utility model will be rendered by reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the present utility model and are therefore not to be considered limiting of its scope.

[0022] Figure 1 A structural schematic diagram of a mold assembly according to an embodiment of the present utility model is shown.

[0023] Figure 2 A structural schematic diagram of the inner side of a female mold according to an embodiment of the present utility model is shown.

[0024] Figure 3 A structure schematic view of the outer side of the female mold is shown.

[0025] Figure 4 A structure schematic view of the inner side of the male mold is shown.

[0026] Figure 5 A partial enlarged schematic view of the inner side of the male mold is shown.

[0027] Figure 6 A structure schematic view of the force sensor is shown.

[0028] Figure 7 A structure schematic view of the force measuring device in a first perspective view is shown.

[0029] Figure 8 A structure schematic view of the force measuring device in a second perspective view is shown. DETAILED DESCRIPTION

[0030] The utility model will be further described in connection with specific embodiments and drawings, and more details are set forth in the following description in order to fully understand the utility model, but the utility model can obviously be implemented in many other ways different from the description, and those skilled in the art can make similar generalization, deduction according to actual application without violating the connotation of the utility model, therefore the protection scope of the utility model should not be limited by the content of the specific embodiments.

[0031] The present application uses specific words to describe the embodiments of the present application. As "one embodiment", "other embodiments", and / or "some embodiments" mean a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "other embodiments" or "some embodiments" mentioned in different positions in the specification are not necessarily the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be properly combined.

[0032] It should be noted that, in order to simplify the expression of the present application and help understand one or more embodiments, the description of the embodiments of the present disclosure sometimes combines various features into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the present application are more than the features mentioned in the claims.

[0033] Reference Figure 1 , Figure 1A structural schematic diagram of a mold assembly 100 according to embodiments of the present application is shown. The mold assembly 100 can be used in an integral molding process to produce a load cell 40 including a load cell body 41 and a load cell sensor 30 Figure 1 (not shown in Figure 7 and Figure 8 ).

[0034] As shown in Figure 1 , the mold assembly 100 can include a female mold 10 and a male mold 20. The female mold 10 can have an inner side 12 and an outer side 14, and the male mold 20 can have an inner side 22 and an outer side 24.

[0035] Figure 2 A structural schematic diagram of the inner side 12 of the female mold 10 according to embodiments of the present application is shown. As shown in Figure 2 , the female mold 10 can include two identical female mold cavity walls 11 on the inner side 12. The two female mold cavity walls 11 are symmetrically distributed on the inner side 12 of the female mold 10. The female mold 10 can also include a feed port 13, which can be located between the two female mold cavity walls 11 and communicate with the two female mold cavities formed by the two female mold cavity walls 11.

[0036] Although in the embodiment shown in Figure 2 , the female mold 10 is shown to include two female mold cavity walls 11, in other embodiments, the female mold 10 can include only one female mold cavity wall 11, or more than two female mold cavity walls 11. However, regardless of how many (e.g., one or more) female mold cavity walls 11 the female mold 10 includes, the feed port 13 of the female mold 10 can be adaptively configured to communicate with the female mold cavity formed by the female mold cavity wall(s) 11, thereby allowing the material injected from the feed port 13 to enter the female mold cavity.

[0037] Figure 3 A structural schematic diagram of the outer side 14 of the female mold 10 according to embodiments of the present application is shown. As shown in Figure 3 , the female mold 10 can include a feed port 13 on the outer side 14. The feed port 13 can extend from the outer side 14 of the female mold 10 to the inner side 12 of the female mold 10 to communicate with the female mold cavity at the female mold inner side. At the outer side 14 of the female mold 10, the feed port 13 can be connected with an injection molding machine, which can inject material (e.g., material used to form the body of the load cell) into the female mold cavity formed by the female mold cavity walls 11 via the feed port 13, and further into the male mold cavity formed by the male mold cavity walls 21 Figure 3 (not shown in Figure 4 ). In some embodiments, the injected material can include a melt, such as molten plastic, etc.

[0038] Figure 4A structural schematic diagram of the inner side 22 of the male mold 20 according to an embodiment of the present application is shown. As shown, the male mold 20 can include two identical male mold cavity walls 21. Although in the embodiment shown, the male mold 20 is shown as including two male mold cavity walls 21, in other embodiments, the male mold 20 can include only one male mold cavity wall 21, or more than two male mold cavity walls 21. It should be understood that the number of male mold cavity walls 21 on the inner side of the male mold 20 should be consistent with the number of female mold cavity walls 11 on the inner side of the female mold 10. Figure 4 Figure 4 As shown, the male mold 20 can include two identical male mold cavity walls 21. Although in the embodiment shown, the male mold 20 is shown as including two male mold cavity walls 21, in other embodiments, the male mold 20 can include only one male mold cavity wall 21, or more than two male mold cavity walls 21. It should be understood that the number of male mold cavity walls 21 on the inner side of the male mold 20 should be consistent with the number of female mold cavity walls 11 on the inner side of the female mold 10.

[0039] For example, in one embodiment, if the female mold 10 has only one female mold cavity wall 11 on its inner side, the male mold 20 should also have a corresponding one male mold cavity wall 21 on its inner side. When the female mold 10 and the male mold 20 are closed, the female mold cavity wall 11 can cooperate with the male mold cavity wall 21 to form a body cavity. The body cavity can include a female mold cavity formed by the female mold cavity wall 11 and a male mold cavity formed by the male mold cavity wall 21. When the female mold 10 and the male mold 20 of the mold assembly 100 are closed and the injection molding machine injects material into the mold assembly 100 via the material inlet 13 on the outer side of the female mold 10, the injected material can enter and fill the body cavity, and then solidify in the body cavity to form a body of the force measuring device 40. In this embodiment, the mold assembly 100 can produce only one force measuring device 40 at a time.

[0040] In other embodiments, if the female mold 10 has two (or more than two) female mold cavity walls 11 on its inner side, the male mold 20 should also have a corresponding two (or more than two) male mold cavity walls 21 on its inner side. When the female mold 10 and the male mold 20 are closed, each of the two (or more than two) female mold cavity walls 11 can cooperate with a corresponding male mold cavity wall 21 to form two (or more than two) body cavities. Each body cavity can include a corresponding female mold cavity formed by a corresponding female mold cavity wall 11 and a corresponding male mold cavity formed by a corresponding male mold cavity wall 21. When the female mold 10 and the male mold 20 of the mold assembly 100 are closed and the injection molding machine injects material into the mold assembly 100 via the material inlet 13 on the outer side of the female mold 10, the injected material can enter and fill the two (or more than two) body cavities, and then solidify in the two (or more than two) body cavities to form bodies of the force measuring device 40, respectively. In this embodiment, the mold assembly 100 can produce two (or more than two) force measuring devices 40 at the same time.

[0041] Referring to Figure 4 , each male mold cavity wall 21 can have six limit portions (labeled as 211a, 211b, 211c, 211d, 211e and 211f, respectively). Each limit portion can be used for the force measuring sensor 30 Figure 4 (not shown in the force measuring sensor 30, see Figure 6 ​) to achieve positioning of the one or more load cells 30 at the corresponding limit portions of the male mold cavity wall 21. Although the number of limit portions on each male mold cavity wall 21 is shown as six in Figure 4 , the number of limit portions on the male mold cavity wall 21 can be adjusted as needed, such as to only one limit portion, two or more limit portions.

[0042] Figure 5 A partial enlarged view of the inner side 12 of the male mold 20 according to an embodiment of the present application is shown. In the enlarged view shown, Figure 5 two limit portions 211a and 211b of the male mold cavity wall 21 are shown. As shown, Figure 5 the limit portions 211a and 211b can be configured as limit slots. The load cell 30 (not shown in Figure 5 , see Figure 6 ) can be placed in the limit slot. Similarly, other limit portions of the male mold cavity wall 21 (e.g., limit portions 211c, 211d, 211e, and / or 211f) can also be configured as limit slots. The limit slot can be configured in a shape that is adapted to the outer contour of the load cell 30 to prevent the load cell 30 placed in the limit slot from moving. During the process of producing the load force device 40 using the mold assembly 100, the injection molding machine can inject material (e.g., molten material) into the main cavity of the mold assembly 100 via the material inlet 13 of the female mold 10, at which time the injected material generally has a very strong impact force. By configuring the limit slot in a shape that is adapted to the outer contour of the load cell 30, the load cell 30 placed in the limit slot can be prevented from being displaced under the strong impact force of the injected material, thereby improving the positioning accuracy of the load cell 30 on the load force device 40 produced using the mold assembly 100, and further improving the measurement accuracy of the load force device 40.

[0043] Figure 6 A structural schematic view of the load cell 30 according to an embodiment of the present application is shown. As shown, Figure 6 the outer contour of the load cell 30 is rectangular. The limit slot of the male mold cavity wall 21 can be correspondingly configured as a rectangle (as shown in Figure 5 ) to confine the load cell 30 in the rectangular limit slot, thereby preventing the load cell 30 from being displaced. In other embodiments, the load cell 30 can have an outer contour of other shapes (e.g., circular), and the limit slot of the male mold cavity wall 21 can be correspondingly configured as a circle to confine the load cell 30 in the circular limit slot, thereby preventing the load cell 30 from being displaced.

[0044] As an alternative or supplement to configuring the limiting portion on the male mold cavity wall 21 as a limiting groove, at least one limiting portion on the male mold cavity wall 21 can be configured to include one or more limiting protrusions, such as limiting columns (not shown in the figure). Accordingly, the force sensor 30 can have one or more limiting recesses, such as Figure 6 The limiting hole 31 shown. The positioning of the force sensor 30 at the limiting portion of the male mold cavity wall 21 can be achieved by the installation cooperation between the limiting protrusion (such as the limiting column) of the limiting portion and the limiting recess (such as the limiting hole 31) of the force sensor 30. In some embodiments, each limiting portion on the male mold cavity wall 21 may include at least two limiting columns, and the force sensor 30 may have at least two limiting holes 31. Compared with only using one set of limiting columns and limiting holes to limit the force sensor 30, by using at least two sets of limiting columns and limiting holes to limit the force sensor 30, it is possible to further prevent the strong impact of the injected material from causing the force sensor 30 on the male mold cavity wall 21 to rotate and shift around a single limiting column at the limiting portion when the material (such as molten material) is injected into the main cavity of the mold assembly 100.

[0045] The following describes an example process for producing a force measuring device 40 using the mold assembly 100 shown above in an integrated molding process. It should be understood that the production process of the force measuring device itself does not constitute the subject of protection of the utility model, but the description of the production process of the force measuring device will be helpful in understanding the relevant structure and function of the mold assembly 100.

[0046] Before the mold assembly 100 is used to produce the force measuring device 40, the mold assembly 100 may be in an open mold state, that is, the female mold 10 and the male mold 20 of the mold assembly 100 are separated from each other (eg, Figure 1 At this time, one or more force sensors 30 may be placed at corresponding limiting portions on the male mold cavity wall 21 of the male mold 20 .

[0047] Next, the female mold 10 and the male mold 20 can be moved toward each other (or, the female mold 10 is stationary and the male mold 20 is moved toward the female mold 10; or, the male mold 20 is stationary and the female mold 10 is moved toward the male mold 20) so that the mounting portion inside the male mold 20 (e.g., Figure 4 The four guide posts shown are marked as 25a, 25b, 25c and 25d) and the mounting mating portion inside the female mold 10 (for example, Figure 2 The four guide holes shown, which are marked as 15a, 15b, 15c and 15d respectively, are installed in conjunction with each other to complete the mold closing of the female mold 10 and the male mold 20.

[0048] Next, after the mold halves 10 and 20 are closed, a melt can be injected into the body cavity of the mold assembly 100 via the feed gate 13 by an injection molding machine connected to the feed gate 13 of the mold half 10. The melt injected into the body cavity of the mold assembly 100 can fill the body cavity and come into contact with the load cell 30 on the cavity wall 21 of the male mold half 20.

[0049] Next, the melt injected and filling in the body cavity can cool and solidify in the body cavity to form a load cell body.

[0050] Next, after the melt solidifies in the body cavity, the mold halves 10 and 20 can be moved away from each other (or, the mold half 10 is stationary and the mold half 20 is moved away from the mold half 10; or, the mold half 20 is stationary and the mold half 10 is moved away from the mold half 20). At this time, the load cell 40 formed in the body cavity can be detached from the mold half 10 and left on the mold half 20, or the load cell 40 can be detached from the mold half 20 and left on the mold half 10. Subsequently, an ejection mechanism (not shown in the figures, which can include one or more ejector pins) on the mold half 20 (or the mold half 10) can eject the load cell 40 out of the mold half 20 (or the mold half 10). Thus, the load cell 40 produced by the mold assembly 100 can be obtained.

[0051] Figure 7 A structural schematic diagram of the load cell 40 according to an embodiment of the present application is shown in a first perspective view. Figure 8 A structural schematic diagram of the load cell 40 according to an embodiment of the present application is shown in a second perspective view. The first perspective view and the second perspective view are two perspective views that are substantially opposite to each other. As shown in the figures, Figure 7As shown, the force measuring device 40 can include a force measuring device body 41 (hereinafter referred to as the body 41) and six force sensors (labeled as 30a, 30b, 30c, 30d, 30e, and 30f, respectively). Since the melt is in contact with the force sensors (e.g., force sensor 30a, force sensor 30b, force sensor 30c, force sensor 30d, force sensor 30e, and force sensor 30f) on the male mold cavity wall 21 throughout the process of cooling and setting of the melt, these force sensors can be fixed to predetermined locations of the body 41 as the melt cools and further sets into the body 41 without additional steps to fix the force sensors to the body 41. That is, in the technical solution of the present application, the force sensors can be fixed to the body during the setting of the material used to form the force measuring device body. In this way, the force sensors 30 and the body 41 are fixed together by an integral molding process, and the fixing between the force sensors and the body after integral molding is more secure and less likely to fall off, which in turn can improve the measurement accuracy of the force measuring device 40. By using the mold assembly 100 of the present application to produce the force measuring device 40 in an integral molding process, the production process of the force measuring device 40 can be effectively simplified (e.g., eliminating additional steps to fix the force sensors 30 to the body 41) and mass production of the force measuring device 40 can be achieved, which in turn can shorten the cycle of manufacturing the force measuring device 40 and reduce the cost of manufacturing the force measuring device 40.

[0052] It should be understood that the number of force sensors on the force measuring device 40 can depend on the number of limit portions on the male mold cavity wall 21 of the mold assembly 100 for the force sensors to be placed thereon. For example, in the case where the male mold cavity wall 21 of the mold assembly 100 has only one limit portion for the force sensors to be placed thereon, the force measuring device 40 can include at most one force sensor. For another example, in the case where the male mold cavity wall 21 of the mold assembly 100 has N (N is greater than 1) limit portions for the force sensors to be placed thereon, the force measuring device 40 can include at most N force sensors, such as N or less force sensors. In some embodiments, the force sensors can include strain gauges or other types of force sensors.

[0053] Some example embodiments have been described above. However, it should be understood that various modifications can be made to the above-described example embodiments without departing from the spirit and scope of the present disclosure. For example, if the described techniques are performed in a different order and / or if components in the described systems, architectures, devices, or circuits are combined in different ways and / or are replaced or supplemented by additional components or their equivalents, appropriate results can also be achieved, and these modified other embodiments also fall within the scope of protection of the claims.

Claims

1. A mold assembly characterized by, The mold assembly is for use in an integral molding process to produce a force measurement device comprising a body and one or more force sensors, the mold assembly comprising: a male mold comprising one or more male mold cavity walls, each male mold cavity wall having one or more retaining portions thereon, each retaining portion for placing a respective force sensor; a female mold comprising one or more female mold cavity walls, wherein, when the female mold is mated with the male mold, each of the one or more female mold cavity walls cooperates with a respective one of the one or more male mold cavity walls to form one or more body cavities, each body cavity for containing material for forming a body of a force measurement device.

2. The mold assembly of claim 1, wherein, At least one of the one or more retaining portions is a retaining slot for placing a respective force sensor therein.

3. The mold assembly of claim 2, wherein, The retaining slot is shaped to conform to an outer profile of the respective force sensor to prevent movement of the respective force sensor within the retaining slot.

4. The mold assembly of claim 1, wherein, At least one of the one or more retaining portions comprises a retaining protrusion for cooperating with a retaining recess on a respective force sensor.

5. The mold assembly of claim 4, wherein, The retaining protrusion is a retaining post and the retaining recess is a retaining hole.

6. The mold assembly of claim 5, wherein, Each of the at least one retaining portion comprises at least two retaining posts, each retaining post for cooperating with a respective retaining hole on the respective force sensor.

7. The mold assembly of any one of claims 1-6, wherein, The female mold further comprises a feed port, The feed port is in communication with the one or more body cavities when the female mold is mated with the male mold.

8. The mold assembly of any one of claims 1-6, wherein, The male mold comprises a mounting portion and the female mold comprises a mounting cooperating portion that cooperates with the mounting portion of the male mold, The mounting portion of the male mold and the mounting cooperating portion of the female mold are mounted to each other when the female mold is mated with the male mold.

9. A force measuring device characterized by, The force measurement device is produced using the mold assembly of any one of claims 1-8 and comprises: a body; and one or more force sensors secured to the body.

10. The force measuring device of claim 9, wherein, Each of the one or more force sensors is a strain gauge.

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