Sensor module

Abstract

A sensor module according to an embodiment of the present disclosure comprises: a pressure sensing part for sensing pressure; at least one or more PCB substrates to receive the pressure signal sensed by the pressure sensing portion, process the pressure signal, and then output the signal; and a housing accommodating the at least one or more PCB substrates and connected to an upper end of the pressure sensing portion; wherein the pressure sensing portion includes a sensing port in which a communication hole for pressure transmission is formed, and a pressure sensing element placed on an inner upper side of the sensing port and sensing a change in pressure transmitted through the communication hole; a pressure sensing element including a diaphragm including a horizontal sensing surface and a support portion vertically extending from an edge of the sensing surface, and one or more strain gauges placed on the sensing surface to sense a change in pressure transmitted through the communication hole; and a groove recessed to a predetermined depth is formed in the outer peripheral surface of the support portion.

Description

Technical Field

[0001] The present disclosure relates to a sensor module, and more particularly, to a sensor module for sensing pressure. Background Art

[0002] The sensor module for sensing pressure refers to a pressure measuring device based on a pressure sensing element (eg, a strain gauge), and may also be defined as a pressure transmitter.

[0003] The general sensor module for sensing pressure uses a principle in which the deflection of a diaphragm generates an output of a strain gauge, and is widely used in technical fields including automobiles, environmental facilities, medical devices, and semiconductor industries.

[0004] The sensor module disclosed in Korean Patent Registration No. 10-1794919 (November 1, 2017) (Prior Art 1) has a structure in which another PCB substrate is vertically connected to the upper surface of a horizontally placed PCB substrate. A problem with a conventional sensor module according to this structure is that the connection stability of the PCB assembly is poor.

[0005] In addition, conventional pressure sensor modules including the sensor module disclosed in Korean Patent Publication No. 2015-0052599 (May 14, 2015) (Prior Art 2) have a structure in which leakage pressure of a pressure measuring part is prevented by processing a diaphragm and a body accommodating the diaphragm into a single body. In the case of a structure in which the diaphragm and the body are formed into a single body, it is difficult to process the diaphragm into a thin film, and it is not possible to process the side surface to improve the sensing sensitivity.

[0006] Furthermore, in the case of the conventional single body structure, when the strain gauge is bonded to the diaphragm, there is a disadvantage in that an oxide film is formed on the appearance of the product due to high-temperature firing.

[0007] Furthermore, the conventional sensor module including the prior art 1 has a disadvantage in that it is difficult to assemble because there is no component for determining a direction when assembling the PCB.

[0008] Furthermore, in the case of a structure in which only a circular member is coupled to the inside of a cylindrical housing, when a rotational force is applied to a pin connector of the sensor module, there is a high possibility that an internal PCB or the like may be damaged due to rotation.

[0009] Furthermore, since the internal components are assembled by bonding to prevent the components from being damaged by rotational force and to maintain airtightness, there is a disadvantage in that it is difficult to expect quantitative quality by variables such as the amount of adhesive applied and the curing conditions. Summary of the invention

[0010] Technical issues

[0011] The present disclosure is proposed to improve the above-mentioned problems.

[0012] Technical Solution

[0013] A sensor module for achieving the above-mentioned purpose according to an embodiment of the present disclosure includes: a pressure sensing part, which is used to sense pressure; at least one or more PCB substrates, which are used to receive a pressure signal sensed by the pressure sensing part, process the pressure signal, and then output the signal; and a housing, which accommodates the at least one or more PCB substrates and is connected to the upper end of the pressure sensing part; wherein the pressure sensing part includes: a sensing port, in which a connecting hole for pressure transmission is formed; and a pressure sensing element, which is placed on the inner upper side of the sensing port and senses the change of pressure transmitted through the connecting hole; the pressure sensing element includes: a diaphragm, which includes a horizontal sensing surface and a supporting part extending vertically from the edge of the sensing surface; and one or more strain gauges, which are placed on the sensing surface to sense the change of pressure transmitted through the connecting hole; and the outer peripheral surface of the supporting part is formed with a groove recessed to a predetermined depth.

[0014] Rounded portions are formed in upper and lower ends of the groove, respectively.

[0015] The diaphragm further includes a shoulder extending in a radial direction from a lower end of the support portion, and a body extending downward from a bottom surface of the shoulder, and inner diameters of the support portion, the shoulder, and the body are the same.

[0016] The outer diameter of the body is larger than the outer diameter of the support portion and smaller than the outer diameter of the shoulder portion.

[0017] The diaphragm further includes a boss protruding from a lower surface of the sensing surface.

[0018] The boss protrudes from the center of the sensing surface and is located directly above the communication hole.

[0019] The sensing port includes: a port body in which the communicating hole is formed; and a flange formed on an upper end of the port body, and a diaphragm accommodating groove accommodating the diaphragm is recessed to a predetermined depth from an upper surface of the flange toward a lower side.

[0020] The lower end of the body is seated in the diaphragm accommodating groove, a protrusion protrudes from the bottom of the diaphragm accommodating groove, and the communication hole passes through the protrusion.

[0021] The protrusion tapers in a direction in which a diameter decreases toward an upper end, and an inner lower end portion of the body touches a lower end of the protrusion.

[0022] A buffer coupling groove is recessed from a lower end toward an upper end of the sensing port, and a lower end of the communication hole is connected to the buffer coupling groove.

[0023] The pressure sensing portion further includes a bumper inserted at a lower end of the sensing port.

[0024] Inside the buffer, a wrench groove is recessed upward from a lower end of the buffer; and a decompression slit is formed extending from a center of an upper surface of the wrench groove to an upper end of the buffer.

[0025] Screw threads are formed on an outer circumferential surface of the buffer and an inner circumferential surface of the buffer coupling groove, respectively, and thus, the buffer is screw-connected into the buffer coupling groove.

[0026] The lower end of the body is welded to the bottom of the diaphragm accommodating groove.

[0027] Advantageous Effects of the Invention

[0028] The sensor module having the above-described configuration according to the embodiment of the present disclosure has the following effects.

[0029] 1. There is an advantage in that, by installing ground pins made of metal with strong shear force at multiple points in the axial direction of the sensor module, damage to the wiring of the internal components can be minimized when external forces including rotational forces act on external components wired to the internal circuit components.

[0030] 2. By not adopting a bonding application method for preventing the internal components from rotating, there are advantages in that uniform quality can be maintained and the manufacturing process can be shortened.

[0031] 3. Since grooves or holes are formed in the PCB substrate for a plurality of ground pins to pass through, there is an effect that the assembly position of the PCB substrate is accurately determined, thereby preventing reverse assembly or misassembly between components.

[0032] 4. Since the diaphragm and the sensing port are manufactured separately and then joined by welding, there is an advantage in that it is easy to process a groove on the side of the diaphragm to improve the sensing sensitivity. In addition, since the sensing port is not inserted into a sintering furnace when the strain gauge is attached to the diaphragm, there is an advantage in that an oxide film is not formed on the appearance of the sensing port.

[0033] 5. By forming a groove on the side of the diaphragm, the thermal strain of the sensing surface caused by temperature change is reduced, thereby reducing the rate of change of the offset according to the temperature. In addition, a more stable pressure is applied to the sensing surface, so that the strain rate increases, and the output value of the strain gauge increases according to the pressure application, thereby improving the accuracy of the pressure sensor.

[0034] 6. Since the boss is formed on the lower surface of the sensing surface, the strain distribution caused by the pressure change increases or decreases linearly, thereby increasing the linearity of the strain. In addition, there is an advantage in that the durability of the sensor module is improved by increasing the safety factor of the diaphragm due to the relative diaphragm displacement and stress reduction. In addition, since the boss is formed on the lower surface of the sensing surface, the strain rate of the sensing surface is increased, thereby increasing the output value of the strain gauge and reducing the error rate.

[0035] 7. Since a buffer is provided, the irregular pulsating pressure caused by valve opening / closing is mitigated, thereby reducing the possibility of damaging the sensing surface and thus improving durability.

[0036] 8. The boss protruding from the bottom of the accommodating groove where the diaphragm is seated has a truncated cone shape, and the lower end portion of the diaphragm is formed into an annular shape, so a separate mechanism is not required to fix the diaphragm during welding.

[0037] 9. Since the buffer is threaded into the sensing port instead of press-fitting, there is an advantage in that the risk factor that occurs during press-fitting is eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a perspective view showing an appearance of a sensor module according to an embodiment of the present disclosure.

[0039] Figure 2 is an exploded perspective view showing the sensor module.

[0040] Figure 3 It is along Figure 1 A longitudinal cross-sectional view of the sensor module taken along line 3-3 in FIG.

[0041] Figure 4 It is along Figure 1 A longitudinal cross-sectional view of a sensor module according to an embodiment of the present disclosure, taken along line 4 - 4 .

[0042] Figure 5 is a perspective view showing the appearance of the sensor module with the housing and the cover removed.

[0043] Figure 6 is a perspective view showing a coupled state of a spacer, a ground terminal, and a ground pin according to an embodiment of the present disclosure.

[0044] Figure 7 is a perspective view showing the spacer viewed from one side.

[0045] Figure 8 is a perspective view showing the spacer viewed from the other side.

[0046] Fig. 9 is a perspective view showing a signal input substrate mounted on a sensor module according to an embodiment of the present disclosure.

[0047] Fig.10 is a perspective view showing a signal processing substrate mounted on a sensor module according to an embodiment of the present disclosure.

[0048] Fig.11 is a bottom perspective view showing a signal output substrate mounted on a sensor module according to an embodiment of the present disclosure.

[0049] Fig.12 is a perspective view showing a ground terminal provided in a sensor module according to an embodiment of the present disclosure.

[0050] Fig.13 is a perspective view showing a pressure sensing portion according to an embodiment of the present disclosure.

[0051] Fig.14 is an exploded perspective view showing a pressure sensing unit.

[0052] Fig.15 It is along Fig.13 A longitudinal cross-sectional view of the pressure sensing portion taken along line 15-15 in FIG.

[0053] Fig.16 It is shown Fig.15 An enlarged view of part A of FIG.

[0054] Fig.17 is a diagram showing a comparison between the strain distribution in a case where the boss exists in the diaphragm and the strain distribution in a case where the boss does not exist in the diaphragm. DETAILED DESCRIPTION

[0055] Hereinafter, a sensor module according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0056] Figure 1 is a perspective view showing the appearance of a sensor module according to an embodiment of the present disclosure, Figure 2 is an exploded perspective view showing a sensor module, Figure 3 It is along Figure 1 A longitudinal cross-sectional view of the sensor module taken along line 3-3 in FIG.

[0057] Reference Figures 1 to 3The sensor module 10 according to an embodiment of the present disclosure includes a housing 12 in a hollow cylindrical shape, a pressure sensing part coupled to a lower end of the housing 12 , and a cover 13 coupled to an upper end of the housing 12 .

[0058] In detail, the pressure sensing portion may include a sensing port 11 and a diaphragm 14 mounted to the sensing port 11. One or more strain gauges 25 (see Fig.13 ) is mounted on the diaphragm 14 to sense a change in pressure transmitted to the inside of the sensing port 11. The combination of the diaphragm 14 and the strain gauge 25 may be defined as a pressure sensing element.

[0059] In addition, the sensor module 10 further includes a plurality of PCB substrates for reading, processing and outputting pressure sensing signals transmitted from the pressure sensing part to the outside and a spacer 19 supporting the plurality of PCB substrates. The function and operation of the spacer 19 will be described in more detail below with reference to the accompanying drawings.

[0060] The plurality of PCB substrates may include a first substrate 15 positioned directly above the diaphragm 14 and a second substrate 16 positioned inside the spacer 19 .

[0061] The plurality of PCB substrates may further include a third substrate 17 that is selectively placed on an upper end of the spacer 19 according to product design conditions.

[0062] Furthermore, the first substrate 15 may be defined as a signal input substrate, the second substrate may be defined as a signal processing substrate, and the third substrate may be defined as a signal output substrate.

[0063] In detail, a pressure signal from the pressure sensing part is read from the first substrate 15, and the signal transmitted from the first substrate 15 is processed by the second substrate 16. In addition, the pressure measurement value processed by the second substrate 16 is output from the third substrate 17 to the outside.

[0064] Furthermore, the sensor module 10 further includes a ground terminal 20 coupled to the outer surface of the spacer 19. The inner peripheral surface of the ground terminal 20 may be coupled to the outer peripheral surface of the spacer 19 by an adhesive member 22 such as a double-sided tape.

[0065] The sensor module 10 may further include a membrane 23. In detail, the communication hole 121 is formed in the housing 12 to allow air to circulate between the inside and the outside of the housing 12 so that air pressures inside and outside the housing are balanced.

[0066] Furthermore, the air introduced through the communication hole 121 passes through the film 23, and moisture contained in the air is filtered so that only the air is introduced into the housing 12. As a result, it is possible to prevent electrical problems from occurring in a plurality of PCB substrates due to moisture.

[0067] The sensor module 10 further includes a ground pin 21 inserted into the spacer 19. The internal circuit components and other internal components are prevented from being damaged by an external rotational force applied to the sensor module 10 by the ground pin 21. A pair of ground pins 21 may be provided.

[0068] The sensor module 10 may further include a sealing ring 18 provided in close contact between the housing 12 and the cover 13. The sealing ring 18 may be an O-ring, but is not limited thereto.

[0069] One or more terminal pins 24 may be inserted into the cover 13 .

[0070] Figure 4 It is along Figure 1 A longitudinal cross-sectional view of a sensor module according to an embodiment of the present disclosure taken along line 4-4, and Figure 5 is a perspective view showing the appearance of the sensor module with the housing and the cover removed.

[0071] Reference Figure 4 and Figure 5 A pin insertion hole 131 into which the upper portion of the ground pin 21 is inserted is formed in the cover 13 constituting the sensor module 10 according to the embodiment of the present disclosure. In addition, a sealing groove 132 into which the sealing ring 18 is fitted is formed on the side surface of the cover 13. The depth of the sealing groove 132 is smaller than the diameter of the sealing ring 18, so that when the cover 13 is fitted to the upper side of the housing 12, the outer surface of the sealing ring 18 is in close contact with the inner surface of the housing 12.

[0072] The ground pin 21 further protrudes a predetermined length from the upper surface of the spacer 19 when inserted into the spacer 19 , penetrates the third substrate 17 placed on the upper end of the spacer 19 , and is then inserted into the pin insertion hole 131 of the cover 13 .

[0073] The ground pin 21 is made of a conductor with high shear strength and serves as a passage for facilitating charge movement, thereby preventing malfunction of the sensor module 10 and damage to components due to introduction of static electricity or abnormal charge. As an example, the ground pin 21 may be made of a metal material.

[0074] A recessed portion 111 accommodating the diaphragm 14 may be formed in the sensing port 11. The recessed portion 111 may have a predetermined diameter, and may be provided in a shape recessed to a predetermined depth from an upper surface of the sensing port 11 toward a lower side.

[0075] Furthermore, a support sleeve 112 extends from an upper surface of the sensing port 11 , and the first substrate 15 is placed inside the support sleeve 112 .

[0076] Figure 6is a perspective view showing a connection state of a spacer, a ground terminal, and a ground pin according to an embodiment of the present disclosure, Figure 7 is a perspective view showing the spacer viewed from one side, and Figure 8 is a perspective view showing the spacer viewed from the other side.

[0077] Reference Figure 6 , the ground terminal 20 is coupled to the outer peripheral surface of the spacer 19 , and the ground pin 21 penetrates a part of the ground terminal 20 and is inserted into the spacer 19 .

[0078] Reference Figure 7 and Figure 8 The spacer 19 includes a body 191 and a pin support boss 192 extending upward from the body 191. For example, the body 191 may have a cylindrical shape or a sleeve shape having a predetermined height. A pair of pin support bosses 192 may be provided.

[0079] In detail, the pair of pin supporting bosses 192 are formed at positions spaced apart from each other at an angle less than 180 degrees along the circumferential direction of the body 191 .

[0080] More specifically, the angle formed by the line connecting one of the pair of pin supporting bosses 192 and the center of the body 191 and the line connecting the other of the pair of pin supporting bosses 192 and the center of the body 191 is less than 180 degrees and may be, for example, 120 degrees.

[0081] The pin insertion groove 193 is formed at the center of the pin support boss 192 to a predetermined depth, and the ground pin 21 is inserted into the pin insertion groove 193. The depth of the pin insertion groove 193 is smaller than the length of the ground pin 21.

[0082] The pin support boss 192 extending upward and the ground pin 21 inserted into the pin insertion groove 193 perform a guiding function to determine the assembly direction of the directional components during the assembly of multiple PCB substrates. In addition, through the pin support boss 192 and the ground pin 21, multiple components can be assembled at a precise position, thereby achieving precise connection between connectors.

[0083] In addition, a portion of the ground pin 21 can be inserted into the spacer 19, and in particular, can be inserted into the pin support boss 192, thereby preventing the ground pin 21 from being bent by an external force. In addition, another portion of the ground pin 21 is inserted into the cover 13. At this time, since another portion of the ground pin 21 passes through the ground terminal 20 and is inserted into the cover 13, the ground terminal 20 can be prevented from being separated from the spacer 19.

[0084] Furthermore, the fixing protrusions 197 protrude from the bottom surface of the body 191 corresponding to the lower ends of the pin supporting bosses 192 to accurately set the assembly position of the first substrate 15 and prevent a phenomenon in which the first substrate 15 is spaced or separated from the assembly position.

[0085] The adhesive member placement portion 195 is formed at a point on the outer peripheral surface of the body 191, and the adhesive member 22 is attached to the adhesive member placement portion 195. As described above, the adhesive member 22 may be a double-sided tape having one side attached to the body 191 and the other side attached to the inner peripheral surface of the ground terminal 20.

[0086] Furthermore, a communication hole 195 (or a communication groove) is formed at one point of the body 191 and is aligned with the communication hole 121 of the housing 12. Furthermore, a film seating portion 196 is formed at a portion where the communication hole 195 is formed.

[0087] The film seating portion 196 may be formed stepwise from the outer peripheral surface of the body 191 to a depth corresponding to the thickness of the film 23. In addition, the communication hole 195 may be formed at the center of the film seating portion 196. In addition, the communication hole 195 may be formed to be recessed from the upper end of the body 191 to the lower side to a predetermined depth.

[0088] Meanwhile, the substrate seating jaws 194 are formed on the inner peripheral surface of the body 191, and the signal processing substrate 16 is seated on the substrate seating jaws 194. In addition, the pin support bosses 192 are formed with a cross-sectional size protruding from the inner peripheral surface of the body 191 toward the center, so that when the signal processing substrate 16 is seated on the substrate seating jaws 194, the signal processing substrate can be assembled at a set seating position or direction of the signal processing substrate 16.

[0089] The substrate seating jaw 194 is formed at a point spaced downward from the upper end of the body 191, and vertically bisects the communication hole 195. Therefore, in a state in which the signal processing substrate 16 is placed on the substrate seating jaw 194, external air introduced into the communication hole 195 is divided into the upper and lower sides of the signal processing substrate 16 to flow.

[0090] By forming the connecting holes 195 and 121, the air pressure inside and outside the sensor module 10 is kept the same, so that accurate pressure measurement can be performed, and since the air introduced into the connecting hole 195 is divided into the upper and lower parts of the signal processing substrate 16, there is an advantage in that air circulation can be smoothly performed inside the sensor module 10.

[0091] Furthermore, since only air excluding moisture contained in the external air is introduced into the sensor module 10 through the membrane 23 , the possibility of electrical problems due to moisture in the internal components is eliminated or significantly reduced.

[0092] Fig. 9 is a perspective view showing a signal input substrate mounted on a sensor module according to an embodiment of the present disclosure.

[0093] In detail, the first substrate 15 may be placed on the upper surface of the sensing port 11 , wherein the first substrate may be placed inside the supporting sleeve 112 .

[0094] In addition, the connector 151 may be mounted on the upper surface of the first substrate 15, and the protrusion groove 152 and the fastening groove 153 may be formed at the edge of the first substrate 15. A pair of the protrusion grooves 152 may be provided, and a plurality of fastening grooves 153 may be provided.

[0095] The protrusion groove 152 is a groove in which the fixing protrusion 197 protruding from the lower end of the spacer 19 is accommodated, and the fastening member is inserted into the fastening groove 153. A plurality of fastening grooves 153 may be provided, for example, two fastening grooves may be provided, and the two fastening grooves 153 may be formed at positions facing each other, but is not limited thereto.

[0096] The fastening member S passes through the fastening groove 153 and is inserted into the sensing port 11, so that the signal input substrate 15 is fixed to the sensing port 11. In addition, by fitting the fixing protrusion 197 into a pair of protrusion grooves 152 forming an angle less than 180 degrees along the circumferential direction, the spacer 19 is automatically and accurately placed in the installation position.

[0097] Fig.10 is a perspective view showing a signal processing substrate mounted on a sensor module according to an embodiment of the present disclosure.

[0098] Reference Fig.10 , the second substrate 16 is placed on the substrate seating jaw 194 and is spaced apart from the first substrate 15 .

[0099] The lower connector 161 is mounted on the lower surface of the second substrate 16 , and the upper connector 162 is mounted on the upper surface. Also, the lower connector 161 is coupled to the connector 151 of the first substrate 15 , and the lower connector 161 and the connector 151 are coupled in the inner space of the spacer 19 .

[0100] In addition, the boss fitting groove 163 may be recessed at the edge of the second substrate 16. The boss fitting groove 163 is a groove in which the pin supporting boss 192 is accommodated. Therefore, a pair of the boss fitting grooves 163 may be provided.

[0101] The pin support boss 192 protrudes from the inner peripheral surface of the body 191 toward the center, and the protrusion is inserted into the boss fitting groove 163. When a pair of pin support bosses 192 are inserted into a pair of boss fitting grooves 163, the second substrate 16 is automatically placed in an accurate installation position. As a result, when the second substrate 16 is placed on the substrate seating jaws 194, the lower connector 161 is accurately coupled to the connector 151 of the first substrate 15.

[0102] Fig.11 is a bottom perspective view showing a signal output substrate mounted on a sensor module according to an embodiment of the present disclosure.

[0103] Reference Fig.11 , a connector 173 coupled to the upper connector 162 is disposed on the lower surface of the third substrate 17 .

[0104] In detail, a pin insertion hole 171 and one or more fastening holes 172 are formed at the edge of the third substrate 17 .

[0105] The pin insertion holes 171 are holes through which the pair of ground pins 21 inserted into the pair of pin support bosses 192 pass, and are spaced apart at an angle less than 180 degrees in the circumferential direction. A pair of the pin insertion holes 171 may be provided.

[0106] When the ground pin 21 passes through the pin insertion hole 171 , the third substrate 17 is automatically placed at a precise mounting position.

[0107] like Figure 5 As shown in FIG. 1 , the third substrate 17 is horizontally placed on the upper surfaces of a pair of pin supporting bosses 192 .

[0108] Furthermore, one or more terminal pins 24 pass through the cover 13, and are inserted into one or more fastening holes 172 formed in the third substrate 17. Thus, the third substrate 17 is fixed to the cover 13 and the pin support bosses 192 at the same time.

[0109] Fig.12 is a perspective view showing a ground terminal provided in a sensor module according to an embodiment of the present disclosure.

[0110] Reference Fig.12 , the ground terminal 20 can be made of a conductive metal material.

[0111] In detail, the ground terminal 20 includes: a terminal body 201 that is rounded in the form of a portion of the outer circumferential surface surrounding the spacer 19; and an extension end 203 that extends and bends from both side edges of the upper end portion of the terminal body 201. A pair of extension ends 203 may be provided, and the pair of extension ends may be spaced apart at an angle less than 180 degrees in the circumferential direction of the terminal body 201. A pin insertion hole 204 is formed in the extension end 203.

[0112] The extension end 203 is placed on the upper surface of the pin support boss 192 so that the pin insertion hole 204 is aligned with the pin insertion groove 193 of the pin support boss 192. The ground pin 21 passes through the pin insertion hole 204 and is inserted into the pin insertion groove 193.

[0113] The ground terminal 20 is accurately placed at the mounting position by placing the extension end 203 on the upper end of the pin support boss 192. In addition, the ground terminal 20 is fixed to the spacer 19 by the adhesive member 22 inserted between the inner peripheral surface of the terminal body 201 and the outer peripheral surface of the spacer 19, and further, the ground terminal 20 is more stably fixed to the spacer 19 by the ground pin 21 passing through the hole 204.

[0114] At the same time, one or more protrusions 202 may protrude from the outer peripheral surface of the terminal body 201. The one or more protrusions 202 are in close contact with the inner peripheral surface of the housing 12 to increase contact resistance. As a result, the phenomenon in which the ground terminal 20 fluctuates along the circumferential direction inside the housing 12 can be minimized.

[0115] Fig.13 is a perspective view showing a pressure sensing portion according to an embodiment of the present disclosure, Fig.14 is an exploded perspective view showing a pressure sensing portion, and Fig.15 It is along Fig.13 A longitudinal cross-sectional view of the pressure sensing portion taken along line 15-15 in FIG.

[0116] Reference Figures 13 to 15 The pressure sensing portion constituting the sensor module 10 according to the embodiment of the present disclosure includes a sensing port 11 , a diaphragm 14 , and a strain gauge 25 .

[0117] In detail, the pressure sensing part may further include a buffer 26 fitted to the lower end of the sensing port 11 .

[0118] More specifically, the sensing port 11 includes a port body 111 and a flange 112 formed on an upper end of the port body 111. The outer diameter of the flange 112 is designed to be larger than that of the port body 111 so that the sensing port 11 may have a T-shaped longitudinal section.

[0119] The diaphragm accommodating groove 115 may be recessed to a predetermined depth inside the flange 112. The buffer coupling groove 116 and the communicating hole 117 are formed inside the port body 111, and the central axis of the port body 111 is coaxial with the central axis of the buffer coupling groove 116 and the communicating hole 117.

[0120] A thread is formed on the inner circumferential surface of the buffer coupling groove 116 . A lower end of the communication hole 117 communicates with an upper end of the buffer coupling groove 116 , and an upper end of the communication hole 117 communicates with the diaphragm accommodating groove 115 .

[0121] The protrusion 118 protrudes from the bottom of the diaphragm accommodating groove 115, and the communication hole 117 passes through the protrusion 118. The protrusion 118 is formed in the shape of a truncated cone that tapers in a direction in which the diameter decreases toward the upper end.

[0122] A circular sleeve 113 is formed on the upper surface of the flange 112 corresponding to the outside of the diaphragm accommodating groove 115 , and the first substrate 15 and the spacer 19 are seated on the inside of the sleeve 113 .

[0123] Meanwhile, the buffer 26 is inserted into the buffer coupling groove 116 and serves to prevent product damage due to pulsating pressure.

[0124] In detail, the threads 261 are formed on the outer circumferential surface of the buffer 26 , and are engaged with threads formed on the inner circumferential surface of the buffer coupling groove 116 to be threadedly coupled to the port body 111 .

[0125] The wrench groove 263 and the decompression slit 262 are formed inside the buffer 26. The decompression slit 262 extends from the upper surface of the wrench groove 263 to the upper surface of the buffer 26, and when abnormal pressure is introduced into the buffer 26, the pulsating pressure is released by allowing the abnormal pressure to pass through the decompression slit 262. As a result, a phenomenon in which the pressure sensing surface of the diaphragm 14 is damaged can be prevented. The buffer 26 may be made of a stainless steel material.

[0126] The diameter of the decompression slit 262 is determined by the pressure range sensed by the sensor module 10. In other words, when the pressure range sensed by the sensor module 10 increases, the diameter of the decompression slit 262 may increase, and when the pressure range sensed by the sensor module 10 decreases, the diameter of the decompression slit 262 may also decrease. In addition, the diameter of the decompression slit 262 may be changed according to the response time of the sensor module 10. When the diameter of the decompression slit 262 is larger, the response time of the sensor module 10 is faster, and when the diameter of the decompression slit 262 is smaller, the response time of the sensor module 10 becomes slower.

[0127] The diaphragm 14 is seated in the diaphragm accommodating groove 115 and welded to the diaphragm accommodating groove 115 .

[0128] In detail, the diaphragm 14 includes: a cylindrical body 141; a shoulder 142 formed at the upper end of the body 141 and having an outer diameter larger than the outer diameter of the body 141; a support portion 143 extending further upward from the upper surface of the shoulder 142; and a sensing surface 144 formed on the upper end of the support portion 143.

[0129] The body 141 , the shoulder 142 , and the support 143 may have a cylindrical shape having the same inner diameter. The support 143 may have a thickness smaller than that of the body 141 .

[0130] One or more strain gauges 25 are attached to the upper surface of the sensing surface 144. To improve the pressure resistance of the one or more strain gauges 25 mounted on the upper surface of the sensing surface 144, silicone, silicone oil, etc. may be applied to the strain gauges 25 and at least a portion of the sensing surface 144.

[0131] The groove 145 is formed with a predetermined depth and width around the outer peripheral surface of the support portion 143. By forming the groove 145, the thermal strain of the sensing surface 144 due to the temperature change is reduced, and the rate of change of the offset according to the temperature is reduced. In addition, the applied pressure acts more stably on the sensing surface 144, so that the strain rate increases, and as the strain rate increases, the output value of the strain gauge 25 also increases, thereby improving the accuracy.

[0132] The smaller the rate of change of the offset with temperature, the smaller the temperature drift or thermal drift, and it can be understood that it is insensitive to temperature changes. Therefore, since the sensing surface 144 of the diaphragm 14 receives less mechanical stress, the durability of the strain gauge 25 is improved, and as the temperature drift is reduced, the sensing performance of the strain gauge is improved.

[0133] Furthermore, since the protrusion 118 extending from the bottom of the diaphragm accommodating groove 115 tapers in a conical shape, when the opened lower surface of the diaphragm 14 is seated on the protrusion 118, since the diaphragm 14 is fixed without shaking, a separate structure for holding the diaphragm 14 is not required during welding.

[0134] Specifically, the lower end of the body 141 of the diaphragm 14 is fixed to the diaphragm accommodating groove 115 by welding. At this time, the welding machine contacts the upper surface of the shoulder 142, and the lower end of the body 141 is placed on the bottom of the diaphragm accommodating groove 115. Since the diameter of the lower end of the protrusion 118 is formed to the side corresponding to the inner diameter of the body 141, in a state where the lower end of the body 141 is in contact with the bottom of the diaphragm accommodating groove 115, a phenomenon in which the diaphragm 14 vibrates in the radial direction and is eccentric to the center of the diaphragm accommodating groove 115 in the radial direction does not occur. In addition, since the upper surface of the diaphragm 14 is pressed by the welding device, the diaphragm does not fluctuate even in the axial direction. Therefore, when the inner edge portion and the outer edge portion of the lower end of the body 141 are connected to the diaphragm accommodating groove 115 by condenser welding, a separate mechanical structure for supporting the diaphragm 14 is not required.

[0135] In addition, a boss 146 may protrude from the center of the lower surface of the sensing surface 144. The boss 146 is formed at the center of the sensing surface 144 and is located directly above the communication hole 117. Since the boss 146 is formed, the nonlinearity of the strain can be improved by linearly increasing or decreasing the strain distribution as the pressure increases or decreases.

[0136] Fig.16 It is shown Fig.15 An enlarged view of part A of FIG.

[0137] Reference Fig.16 as well as Fig.15 The groove 145 is recessed to a predetermined depth on the outer peripheral surface of the support portion 143 of the diaphragm 14 , and the groove 145 may be continuously surrounded in a band shape on the outer peripheral surface of the support portion 143 .

[0138] In addition, a rounded portion 1421 bent with a predetermined curvature may be formed at a corner portion where the support portion 143 and the shoulder portion 142 intersect. In addition, rounded portions 1451 and 1452 rounded with a predetermined curvature may be formed at the upper end and the lower end of the groove 145, respectively, and the rounded portions 1451 and 1452 may be defined as an upper rounded portion 1451 and a lower rounded portion 1452, respectively.

[0139] Since the rounded portions 1451 , 1452 , and 1421 are respectively formed, it is possible to prevent the corner portions where the rounded portions are formed from being damaged due to stress concentration.

[0140] Fig.17 is a diagram showing a comparison between the strain distribution in a case where the boss exists in the diaphragm and the strain distribution in a case where the boss does not exist in the diaphragm.

[0141] For reference, the vertical axis (y-axis) of the strain distribution graph represents the strain output value, and the horizontal axis (x-axis) represents each point of the sensing surface 144 .

[0142] Reference Fig.17 , when the boss 146 protrudes from the center of the lower surface of the sensing surface 144, it can be seen that the strain distribution increases or decreases linearly as shown by the solid line. On the other hand, when there is no boss 146, it can be confirmed that the strain distribution increases or decreases nonlinearly as shown by the dotted line.

[0143] Furthermore, it can be confirmed that the strain output value when the boss 146 exists is larger than the stress output value when the boss 146 does not exist. As the strain output value increases, the sensing error rate decreases and the accuracy increases.

Claims

1. A sensor module, comprising: A pressure sensing unit, the pressure sensing unit is used to sense pressure; At least one or more PCB substrates, the at least one or more PCB substrates are used to receive the pressure signal sensed by the pressure sensing part, process the pressure signal, and then output a signal; as well as a housing that accommodates the at least one or more PCB substrates and is coupled to an upper end of the pressure sensing portion, Wherein, the pressure sensing unit comprises: a sensing port in which a communication hole for pressure transmission is formed; and a pressure sensing element placed on an inner upper side of the sensing port and sensing a change in pressure transmitted through the communication hole, Wherein, the pressure sensing element comprises: a diaphragm including a horizontal sensing surface and a support portion extending vertically from an edge of the sensing surface; and one or more strain gauges placed on the sensing surface to sense changes in pressure transmitted through the communicating hole, and Wherein, a groove recessed to a predetermined depth is formed on the outer peripheral surface of the support portion.

2. The sensor module according to claim 1, in, Rounded portions are formed in upper and lower ends of the groove, respectively.

3. The sensor module according to claim 1 or 2, in, The diaphragm further comprises: a shoulder extending in a radial direction from a lower end of the support portion; and a body extending downwardly from a bottom surface of the shoulder, and Wherein, the inner diameters of the support portion, the shoulder portion and the body are the same.

4. The sensor module according to claim 3, in, The outer diameter of the body is larger than the outer diameter of the support portion and smaller than the outer diameter of the shoulder portion.

5. The sensor module according to claim 1, in, The diaphragm further includes a boss protruding from a lower surface of the sensing surface.

6. The sensor module according to claim 5, in, The boss protrudes from the center of the sensing surface and is located directly above the communication hole.

7. The sensor module according to claim 3, in, The sensing port comprises: a port body in which the communication hole is formed; and a flange formed on an upper end of the port body, and The diaphragm accommodating groove for accommodating the diaphragm is recessed from the upper surface of the flange to a predetermined depth toward the lower side.

8. The sensor module according to claim 7, in, The lower end of the body is placed in the diaphragm accommodating groove, wherein a protrusion protrudes from the bottom of the diaphragm accommodating groove, and Wherein, the communicating hole passes through the protrusion.

9. The sensor module according to claim 8, in, The protrusion tapers in a direction in which the diameter decreases toward the upper end, and Wherein, the inner lower end portion of the body touches the lower end of the protrusion.

10. The sensor module according to claim 1, in, The pressure sensing portion further includes a bumper inserted at a lower end of the sensing port.

11. The sensor module according to claim 10, in, The buffer coupling groove is recessed from the lower end to the upper end of the sensing port, and Wherein, the lower end of the communicating hole is connected to the buffer coupling groove.

12. The sensor module according to claim 10, in, Inside the buffer, The wrench groove is recessed upward from the lower end of the buffer, and A decompression slit is formed extending from a center of an upper surface of the wrench groove to an upper end of the buffer.

13. The sensor module according to claim 11, in, Screw threads are formed on an outer circumferential surface of the buffer and an inner circumferential surface of the buffer coupling groove, respectively, and thus, the buffer is screw-connected into the buffer coupling groove.

14. The sensor module according to claim 9, in, The lower end of the body is welded to the bottom of the diaphragm accommodating groove.

Images