JPH09210812A - Sensing element - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To prevent breakage of a conductive wire forming a sensing element to facilitate handling and improve reliability. A holding member is fixed to a magnetic core member, and a connecting portion connecting an external connection lead wire and an end portion of the conductive wire is mechanically fixed and held in an insulated state from the magnetic core member. Unnecessary tensile stress can be prevented from being applied to the wire, and disconnection of the conductor wire having weak mechanical strength does not occur. Therefore, handling at the time of assembling can be facilitated and the reliability of the sensing element can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensing element, and more particularly to a magnetostrictive sensing element for measuring a load.

[0002]

2. Description of the Related Art Conventionally, for large vehicles such as trucks, the load has been measured to prevent overloading. This is because overloading impairs the operability of the vehicle itself and causes not only a traffic accident but also damage to the vehicle and the road surface.

The load capacity of a vehicle has been measured by a load measuring device installed on the road. More specifically, first, a wheel is placed on a loading plate equipped with a load converter, the wheel weight or axle weight of the wheel is measured, and the wheel weight or axle weight is added to obtain the vehicle weight.

Next, the loading weight was calculated by subtracting the weight of the passenger and the own weight of the vehicle from the measured vehicle weight. However, since the above-mentioned conventional load measuring device has a large measuring device and a high installation cost, the installation place and the number of installed devices are very limited.

Therefore, there is a problem that it is not possible to prevent overloading on all vehicles. In order to solve this, the magnetostrictive sensor is installed so as to be sandwiched between the axle case (axle) and the leaf spring, and the amount of strain due to the load applied to the magnetostrictive sensor is measured to determine the loading weight for each vehicle. It is proposed to convert and measure.

A conventional example based on such a proposal will be described below. Two brackets are fixed to the carrier frame at a predetermined interval corresponding to the length of the leaf spring, and one end of the leaf spring is swingably connected to one bracket via a pin. A shackle is swingably connected to the other bracket via a shackle pin, and the other end of the leaf spring is swingably connected to the shackle via a pin.

A leaf spring is attached to the carrier frame via these two brackets, and an axle (not shown) is attached to the carrier frame via the leaf springs. FIG. 7 shows a sectional view of the shackle pin when the sensing element is housed in the shackle pin.

The shackle pin 50 has a through hole 50d extending from one end 50a to the other end 50b. The through hole 50d is a small-diameter portion 50e provided at one end 50a a little from the midpoint of the central axis of the shackle pin 50.
And a first medium diameter portion 50f provided in communication with the small diameter portion 50e in the extending direction of the central axis of the shackle pin 50,
Similarly, the second large diameter portion 50g is provided in communication with the small diameter portion 50e in the extending direction of the central axis of the shackle pin, and the first large diameter portion is provided between the one end 50a and the first intermediate diameter portion 50f. It is provided with a diameter portion 50h and a second large diameter portion 50j provided between the other end 50b and the second medium diameter portion 50g.

The first medium diameter portion 50f and the second medium diameter portion 50g have the same diameter, and a load measuring sensing element 51 is housed inside each of them. As shown in FIG. 8, the sensing element 51 is made of a magnetic material such as permalloy and has a substantially rectangular magnetic core 52 in plan view.
And a conducting wire 53 wound so as to intersect a plurality of winding holes of the magnetic core 52 described later.

The magnetic core 52 has four winding holes 54A,
The coil portion 55 is provided with 54B, and the fixing portions 56 are provided on both sides of the coil portion 55. In this case, a cutout portion 57 having a semicircular cross section is provided between the coil portion 55 and the fixed portion 56 to relieve stress.

As the conducting wire 53, for example, a metal wire of φ0.1 mm coated with an insulating material such as vinyl is used. First, the first conducting wire 53 is formed in the two winding holes 54A of the magnetic core 52. Is wound, and then two second winding holes 54
The second conducting wire 53 is wound around B. As a result, a total of four lead lines 53A are drawn from the magnetic core 52.

The four lead wires 53A are covered with a protective tube 58 made of an insulating material such as vinyl. One of the sensing elements 51 is shown in FIG.
As shown in FIG. 5, the first case assembly 60 accommodates the first case assembly 60 and the first case assembly 60 accommodates the shackle pin 50 in the first medium-diameter portion 50 f.

The other sensing element 51 has a second
The second case assembly 6 is housed in the case assembly 61.
1 and the shackle pin 50 are accommodated in the second medium diameter portion 50 g. The first case assembly 60 and the second case assembly 61 are connected by a conduit pipe 62, and the lead wire 53A from the sensing element 51 housed in the second case assembly 61 is covered by the protective tube 58. It is drawn out to the first case assembly 60 side through the inside of the wire pipe 62, and further to the outside through the inside of the first case assembly 60. Similarly, the lead wire 53A from the sensing element 51 housed in the first case assembly 60 is led to the outside while being covered with the protective tube 58.

Next, the operation when the load is measured using the sensing element 51 housed in the shackle pin 50 will be described. When a load is applied to the shackle pin 50 from the vehicle via both sides of the platform frame and the bracket, a shearing force acts on the shackle pin 50.

As a result, the sensing element 51 arranged inside the shackle pin 50 is distorted to change the sensing output, and the vehicle load is detected based on all of these sensing outputs.

[0016]

In the above-mentioned conventional sensing element, one end of the conducting wire forming the coil is covered with a protective ground tube and used as a lead wire for direct wiring, but the conducting wire is basically a single wire. However, since the diameter is small, it is easy to break the wire at the assembly stage, and it is difficult to improve reliability.

Therefore, it is an object of the present invention to provide a sensing element which can prevent breakage of a conductive wire forming the sensing element to facilitate handling and improve reliability.

[0018]

In order to solve the above problems, the invention according to claim 1 has a plurality of winding holes, a magnetic core member formed of a magnetic material, and the winding holes. And a lead wire for external connection and a lead wire for external connection, which is formed of an insulating material and is fixed to the magnetic core member. And a holding member for mechanically fixing and holding the connecting portion connected to the end portion of the.

According to the first aspect of the present invention, the holding member is fixed to the magnetic core member, and the connecting portion connecting the lead wire for external connection and the end portion of the conductor is insulated from the magnetic core member. Hold mechanically fixed. According to a second aspect of the present invention, in the first aspect of the invention, the magnetic core member has a locking hole for fixing the holding member, and the holding member is locked in the locking hole. It is configured to have a locking piece.

According to the invention of claim 2, in addition to the function of the invention of claim 1, the holding member is fixed to the locking hole of the magnetic core member by the locking piece. The invention according to claim 3 is the invention according to claim 2, wherein the magnetic core member has a plate shape having a first surface and a second surface, and the holding member serves as the locking piece. A first sub-holding member having a sub-locking piece fixed to the first surface side and a second sub-holding piece having the sub-locking piece as the locking piece fixed to the second surface side A sub-holding member is provided.

According to the third aspect of the invention, in addition to the function of the second aspect of the invention, the first sub-holding member of the holding member is provided with the sub-engaging piece to the first surface side of the magnetic core member. The second sub holding member is fixed to the second surface side of the magnetic core member by the sub locking piece. According to a fourth aspect of the invention, in the third aspect of the invention, the locking hole is a through hole penetrating from the first surface to the second surface side, and the sub-holding member is the external member. The first external connection lead wire has an insertion hole for passing a connection lead wire through the locking hole, and the first external connection lead wire is provided on the first auxiliary holding member side. The connecting portion corresponding to a line is provided, and is drawn out to the second sub holding member side through the insertion hole of the first sub holding member, the locking hole, and the insertion hole of the second sub holding member. And the second lead wire for external connection is the second lead wire for external connection.
The connecting portion corresponding to the second lead wire for external connection is provided on the sub-holding member side, and the insertion hole, the locking hole, and the first sub-holding member of the second sub-holding member are provided. It is configured so as to be drawn out to the side of the first sub holding member through the insertion hole.

According to the invention of claim 4, in addition to the function of the invention of claim 3, the first lead wire for external connection is provided on the side of the first auxiliary holding member for the first external connection. A connection portion corresponding to the lead wire is provided, and is drawn out to the second sub holding member side through the insertion hole, the locking hole of the first sub holding member and the insertion hole of the second sub holding member.

The second lead wire for external connection is the second lead wire.
A connecting portion corresponding to the second external connection lead wire is provided on the sub-holding member side of the second sub-holding member through the insertion hole, the locking hole, and the insertion hole of the first sub-holding member. It is pulled out to the first sub holding member side. According to a fifth aspect of the invention, in the third or fourth aspect of the invention, the sub-holding member includes a fixed holding piece for fixing the connecting portion.

According to the invention of claim 5, in addition to the function of the invention of claim 3 or 4, the fixed holding piece of the auxiliary holding member fixes the connecting portion.

[0025]

Preferred embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows an external view of the sensing element. The sensing element 1 is made of a magnetic material such as permalloy, and has a magnetic core 2 having a substantially rectangular shape in plan view,
Conductor 3 wound so as to intersect with a plurality of winding holes of magnetic core 2 described later, lead wires 4A and 4B brazed to the ends of conductor 3, conductor 3 and lead wires 4A and 4B. And an insulating seat 5 that functions as a holding member that holds the connection portion with the magnetic core 2 while maintaining the insulating state.

As shown in FIG. 2, the magnetic core 2 includes a coil portion 11 provided with four winding holes 10A and 10B,
The coil portion 11 is provided with a fixing portion 12 provided on both sides thereof, and a locking hole 13 provided as a through hole in the one fixing portion 12 for locking the insulating seat. In this case, a cutout portion 14 having a semicircular cross section is provided between the coil portion 11 and the fixed portion 12 for relieving stress.

FIG. 3 shows an external view of the insulating seat 5, and FIG.
FIG. 4A is a partial cross-sectional view of the insulator 5 taken along the line AA of FIG.
(B) shows the BB partial cross-section arrow view of the insulator 5. The insulating seat 5 cooperates with a first rim portion 20 for guiding the lead wires 4A, 4B and a second rim portion 22 described later to fix the connection portion between the lead wires 4A, 4B and the conductor wire 3. Of the first locking piece 21 and the connecting portions, the lead wires 4A, 4B and the conductive wire 3 are guided, and the connecting portion of the lead wires 4A, 4B and the conductive wire 3 is machined in cooperation with the first locking piece 21. Second rim portion 22 that is fixedly retained, insertion hole 23 for passing two sets of lead wires (first lead wire and second lead wire), and locking hole 1
And a second locking piece 24 that is inserted into the magnetic core 3 to bring the magnetic core 2 into a locked state.

Here, a method of assembling the sensing element 1 will be described. First, the winding holes 10A, 10 of the magnetic core 2
The first conducting wire R1, which is one of the two conducting wires, is wound around the two winding holes 10A arranged in a line in the longitudinal direction of the magnetic core 2 of B, and after the winding is completed, the magnetic core 2 is wound. The second conducting wire R2, which is the other conducting wire, is wound around the two winding holes 10B arranged in a row in the lateral direction.

Next, one end of the first stranded wire 4A1 constituting the first lead wire 4A and one end of the first conducting wire R1 are brazed by soldering, and one end of the second stranded wire 4A2 constituting the first lead wire 4A. And one end of the second conducting wire R2 are brazed with solder to provide two connecting portions. Similarly, the second lead wire 4B
The one end of the first stranded wire 4B1 and the other end of the first conductive wire R1 are brazed by soldering, and one end of the second stranded wire 4B2 and the other end of the second conductive wire R2 that form the second lead wire 4B Are brazed with solder to provide two connection parts.

Subsequently, the second locking pieces 24 are inserted into the locking holes 13 from both sides of the magnetic core 2, and the two insulating seats 5 are mounted so as to sandwich the magnetic core 2. Then, from one insulating seat 5 side, the insertion hole 23 of the one insulating seat 5, the magnetic core 2
The first lead wire 4A and the second lead wire 4B are passed through the locking hole 13 and the insertion hole 23 of the other insulating seat 5 to the other insulating seat 5 side so as to intersect in the locking hole 13.

Further, as shown in FIG. 1, the first stranded wire 4A1
In the longitudinal direction of the magnetic core 2 and a connecting portion formed by one end of the first conducting wire R1 and a connecting portion formed by one end of the second twisted wire 4A2 and one end of the second conducting wire R2. Then, the connection portions located at the tips of the twisted wires 4A1 and 4A2 are sandwiched between the second rim portion 22 and the first locking piece 21 and fixed.

In the same manner, a connecting portion composed of one end of the first stranded wire 4B1 and the other end of the first conducting wire R1 constituting the second lead wire 4B, one end of the second stranded wire 4B2 and the second Conductor R
2 and the connecting portion constituted by the other end of the magnetic core 2 in the longitudinal direction of the magnetic core 2 so as to be pushed and expanded, and each twisted wire 4
Connect the connecting parts located at the tips of B1 and 4B2 to the second rim part 22.
And the first locking piece 21 for sandwiching and fixing.

As described above, the lead wire 4A and the lead wire 4B intersect in the locking hole 13, and the connecting portion with the conductor wire R1 and the conductor wire R2 is expanded in the longitudinal direction on the insulating seat 5. Since they are mechanically fixed, lead wires 4A, 4
Even if the tensile force is applied to B, the tensile force is not directly applied to the connection portion, and the conductor wire having low mechanical strength is not broken.

Therefore, handling at the time of assembling can be facilitated and reliability can be improved. Further, since wiring can be easily performed depending on the color of the coating of the lead wire, wiring mistakes can be reduced.

Next, a load sensor configured by using the thus-configured sensing element for measuring a load will be described with reference to FIG. Vehicle carrier frame 3
2, two brackets 33 are fixed at a predetermined interval corresponding to the length of the leaf spring 31, and one bracket 33 is swingably connected to one bracket 33 via a pin 33A. Has been done.

A shackle 34 is swingably connected to the other bracket 33 via a shackle pin 30, and the other end of the leaf spring 31 is swingably connected to the shackle 34 via a pin 34A. ing. Through these two brackets 33, the leaf spring 3
1 is attached to the luggage carrier frame 32, and an axle (not shown) is further attached to the luggage carrier frame 32 via the leaf spring 31.

FIG. 6 shows a sectional view of the shackle pin when the sensing element is housed in the shackle pin. The shackle pin has a through hole 30d extending from one end 30a to the other end 30b.

The through hole 30d is in communication with the small diameter portion 30e provided slightly closer to the one end 30a than the midpoint of the center axis of the shackle pin, and the small diameter portion 30e in the extending direction of the center axis of the shackle pin. The first medium diameter portion 30 provided in
f, similarly to the small diameter portion 30e, the second intermediate diameter portion 30j that is provided in communication with the shackle pin in the extending direction of the central axis of the shackle pin
A first large diameter portion 30h provided between the one end 30a and the first medium diameter portion 30f, and a second large diameter portion 30j provided between the other end 30b and the second medium diameter portion 30g. , And are configured.

The first medium diameter portion 30f and the second medium diameter portion 30g are configured to have the same diameter, and the sensing elements 1 for load measurement are housed inside thereof. One sensing element 1 is housed in the first case assembly 41, and is housed together with the first case assembly 41 in the first medium-diameter portion 30f of the shackle pin.

The other sensing element 1 is housed in the second case assembly 42, and the second case assembly 42
Together with this, the shackle pin 30 is housed in the second medium diameter portion 30g. The first case assembly 41 and the second case assembly 42 are connected by a conduit pipe 43, and the lead wire from the sensing element 1 housed in the second case assembly 42 passes through the conduit pipe 43 to form the first case. Assy 4
It is drawn out to the 1 side, and further, it is drawn out through the inside of the first case assembly 41.

Next, the operation when the load is measured using the sensing element 1 housed in the shackle pin 30 will be described. From the vehicle to the carrier frame 32 and the bracket 3
The load G is applied to the shackle pin 30 via both side surfaces 33a of
Is applied, a shearing force acts on the shackle pin 30.

As a result, the sensing element 1 arranged inside the shackle pin 30 is distorted to change the sensing output, and the vehicle load is detected based on all of these sensing outputs. More specifically, for example, when the load distribution in the left-right direction is even with respect to the traveling direction of the vehicle, the point of action of the load G acting on the shackle pin is substantially equal to the axial center position of the shackle pin. Become.

As a result, the load G is applied to each sensing element.
1/2 (= 1/2 G) is evenly applied, and the load G can be detected based on the sensing outputs of both sensing elements. Further, when the load distribution in the left-right direction is uneven with respect to the traveling direction of the vehicle, the point of application of the load G acting on the shackle pin is
Depending on the uneven state, the shackle pin is displaced from the axial center position.

For example, suppose that the point of action of the load G is displaced from the axial center position of the shackle pin by ¼ of the entire length of the shackle pin in the left or right direction.
1 / 4G is applied to one sensing element, and 3 / 4G is applied to the other sensing element.

As a result, the load G actually applied can be detected based on the sensing outputs of both sensing elements. As described above, according to the present embodiment, it is possible to configure a load sensor in which the sensing element can be easily handled and the correct load can be easily obtained.

[0046]

According to the invention described in claim 1, the holding member is fixed to the magnetic core member, and the connecting portion connecting the lead wire for external connection and the end portion of the conductor is insulated from the magnetic core member. Since it is mechanically fixed and held in this state, it is possible to prevent unnecessary tensile stress from being applied to the conductive wire, and disconnection of the conductive wire having weak mechanical strength does not occur.

Therefore, the handling at the time of assembling can be facilitated and the reliability of the sensing element can be improved. According to the invention of claim 2, in addition to the effect of the invention of claim 1, since the holding member is fixed to the locking hole of the magnetic core member by the locking piece, the holding member can be securely attached to the magnetic core member. Can be fixed to.

According to the invention of claim 3, in addition to the operation of the invention of claim 2, the first sub-holding member of the holding member is provided with the sub-engaging piece so that the first surface side of the magnetic core member is provided. Since the second sub-holding member is fixed to the second surface side of the magnetic core member by the sub-engaging piece, the conductor wire can be reliably fixed to both surfaces of the magnetic core member, and the wiring is easy. Becomes

According to the invention of claim 4, in addition to the function of the invention of claim 3, the first lead wire for external connection is provided on the side of the first auxiliary holding member for the first external connection. A connecting portion corresponding to the lead wire is provided, and is drawn out to the second sub holding member side through the insertion hole and the locking hole of the first sub holding member and the insertion hole of the second sub holding member. The second external connection lead wire has a connecting portion corresponding to the second external connection lead wire on the second sub-holding member side, and has an insertion hole, a locking hole, and a second sub-holding member. Since it is pulled out to the first sub-holding member side through the insertion hole of the first sub-holding member, the first external connection lead wire and the second external connection lead wire intersect in the locking hole. Therefore, the tensile force applied to the external connection lead wires due to the frictional force between the external connection lead wires and the side wall of the locking hole, etc. A connection no longer be transmitted to the lead side through, it is possible to obtain a strong sensing elements more conductors disconnected, so that the reliability is further improved.

According to the invention of claim 5, in addition to the effect of the invention of claim 3 or 4, since the fixed holding piece of the auxiliary holding member fixes the connecting portion, the connecting portion itself is also fixed. Since tensile stress and other unnecessary forces are not applied, reliability can be further improved.

[Brief description of drawings]

FIG. 1 is an external view of a sensing element according to an embodiment.

FIG. 2 is an external view of a magnetic core.

FIG. 3 is an external view of an insulating seat.

FIG. 4 is a partial sectional view of an insulating seat.

FIG. 5 is an explanatory view of a mounting state of the load sensor.

FIG. 6 is a cross-sectional view when a sensing element is provided in the shackle pin.

FIG. 7 is a cross-sectional view when a sensing element is provided inside a shackle pin in a conventional example.

FIG. 8 is an external view of a conventional sensing element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sensing element 2 Magnetic core 3 Conductive wire 4A, 4B Lead wire 5 Insulation seat 10A, 10B Winding hole 11 Coil part 12 Fixing part 13 Locking hole 14 Notch part 20 1st rim part 21 1st locking piece 22 2nd Rim portion 23 Insertion hole 24 Second locking piece

Claims (5)

[Claims] 1. A magnetic core member having a plurality of winding holes and formed of a magnetic material, and two conductor wires wound in the winding holes in an intersecting state to form an intersecting coil. In the sensing element including, a holding member formed of an insulating material, fixed to the magnetic core member, and mechanically fixed and holding a connecting portion connecting the external connection lead wire and the end portion of the conductive wire. A sensing element characterized by being provided. 2. The sensing element according to claim 1, wherein the magnetic core member has a locking hole for fixing the holding member, and the holding member has a locking hole for locking in the locking hole. A sensing element having a piece. 3. The sensing element according to claim 2, wherein the magnetic core member has a plate shape having a first surface and a second surface, and the holding member is an auxiliary member as the locking piece. A first sub-holding member having a stop piece and fixed to the first surface side, and a second sub-holding piece having a sub-locking piece as the locking piece and fixed to the second surface side. A sensing element comprising a member. 4. The sensing element according to claim 3, wherein the locking hole is a through hole penetrating from the first surface to the second surface side, and the sub holding member is for external connection. An insertion hole for passing a lead wire through the locking hole is provided, and the first external connection lead wire is provided on the first sub-holding member side to the first external connection lead wire. The corresponding connecting portion is provided, and the insertion hole of the first sub holding member is provided.
The second lead wire for external connection is pulled out to the second sub-holding member side through the locking hole and the insertion hole of the second sub-holding member. The connection portion corresponding to the second lead wire for external connection is provided, and the insertion hole of the second sub-holding member,
A sensing element, which is drawn out toward the first auxiliary holding member side through the locking hole and the insertion hole of the first auxiliary holding member. 5. The sensing element according to claim 3, wherein the auxiliary holding member includes a fixed holding piece for fixing the connecting portion.