JP7037966B2 - Indentation test equipment - Google Patents

Description

The present invention relates to an indentation test device for indenting an indenter into foods such as kamaboko and ham, and soft tissues of humans, and measuring their softness.

The following Patent Document 1 discloses an indentation test device for measuring the softness of a flexible food, a human body tissue, or the like as a subject.
As shown in FIG. 6, this device has a pencil-shaped outer shape, and the indenter 50 pushed into the subject and the indenter 50 pushed into the subject inside the housing 10 forming the outer shape. At that time, a force sensor 30 that detects the force acting on the indenter 50, a calculation unit 40 that calculates Young's modulus for evaluating the softness of the subject based on the force acting on the indenter 50, and the like are housed.
FIG. 7 shows a simplified configuration of this indentation test apparatus. The indenter 50 is housed in the housing 10 so that a certain amount of the hemispherical portion at the tip protrudes from the end surface 11 of the housing 10.

この(数１)を用いて、力センサ３０で検出された押込荷重Ｆから被検体のヤング率Ｅを求めることができる。 The operator who operates this device grips the housing 10 portion and pushes the indenter 50 into the subject until the end face 11 of the housing 10 comes into contact with the subject.
At this time, the force (pushing load) detected by the force sensor 30 when the end surface 11 of the housing 10 comes into contact with the subject is F, and the amount of protrusion of the indenter 50 protruding from the end surface 11 of the housing 10 (that is, that is). Let δ be the amount of indenter 50 pushed into the subject, φ be the diameter of the hemisphere of the indenter 50, E be the Young's modulus of the subject, and ν be the Poisson's ratio peculiar to the subject. There is a relationship represented by (Equation 1).

Using this (Equation 1), the Young's modulus E of the subject can be obtained from the indentation load F detected by the force sensor 30.

This indentation test device can measure the softness of a subject at the place where the subject should be (so-called “in-situ measurement”). In FIG. 8, a push-in test device having a grip portion 60 provided in the housing 10 is used to measure the flexibility of the cushioning material attached to the transport pipe and the hardness of the leg muscles immediately after exercise. It shows how to do it.

WO2017 / 164426

However, in this indentation test device, when the indentation test into the subject is performed, the end face 11 of the housing 10 comes into contact with the subject, so that a part of the subject or dirt adhering to the subject opens the end face 11. There is a risk of invading the inside of the housing 10 from the portion. It takes a lot of time and effort to remove such foreign matter from the inside of the housing 10. In addition, the sticky foreign matter causes a measurement error.

The applicant has previously proposed an indentation test apparatus in which the end face 11 of the housing 10 does not come into contact with the subject during the indentation test (Japanese Patent Application No. 2018-13281).
As shown in FIG. 9, this device includes an indenter 50 that projects a long distance from the end of the housing, and a plurality of pin-shaped contact detection sensors 221 arranged at positions surrounding the indenter 50. The length from the housing to the tip of the indenter 50 is set to be longer than the tip of the contact detection sensor 221 by a distance corresponding to the protrusion amount δ of the indenter 50 in FIG. 7.
When the pin-shaped contact detection sensor 221 comes into contact with a subject, the electric resistance value changes, the vibration state changes, and the frequency characteristic of the applied electric signal changes. By detecting those changes, contact with the subject can be detected.

The operator who operates this device grips the housing of the indentation test device and pushes the indenter 50 into the subject until the contact detection sensor 221 detects the subject. Then, the pushing load acting on the indenter 50 at the time when the contact detection sensor 221 detects the subject is detected by the force sensor 30, and the Young's modulus E of the subject is calculated based on the detection load.
In this device, during the indentation test, the end face 11 of the housing 10 does not come into contact with the subject, and the opening position of the housing 10 where the end face 11 is present is away from the subject, so that a part of the subject or the subject is present. There is an advantage that there is little possibility that the dirt of the material will enter the housing 10.

The present invention is intended to further improve the apparatus of FIG. 9, and an object of the present invention is to provide an indentation test apparatus capable of reliably preventing the intrusion of foreign matter and dirt of the apparatus during the indentation test.

In the present invention, an indenter pushed into a subject, a force sensor that is mechanically coupled to the indenter and detects a force acting on the indenter, a mechanical coupling portion between the indenter's force sensor, and a force sensor are arranged inside. The indenter is mechanically coupled to the force sensor, with at least the tip of the indenter outside the housing, which comprises a housing and a plurality of pin-shaped contact detection sensors supported by the housing so as to surround the indenter. The tip of the indenter is a push-in test device located at a position farther than the tip of the contact detection sensor by a predetermined distance when viewed from the housing, and the circumference excluding the tip of the indenter and the plurality of contact detection sensors is It is characterized in that it is covered with a cover member.
The presence of the cover member can prevent dirt and foreign matter from adhering to the indentation test device during the indentation test.

Further, in the indentation test apparatus of the present invention, it is desirable that the cover member is composed of an inner cover provided with a plurality of through holes through which a contact detection sensor and an indenter are individually inserted, and an outer cover that covers the inner cover from the outside. ..
The double cover further enhances the function of preventing foreign matter from entering.

Further, in the indentation test apparatus of the present invention, it is desirable that a plurality of contact detection sensors are fixed to the sensor holding portion supported by the housing, and the cover member is detachably attached to the sensor holding portion.
By doing this, the cover member can be removed and cleaned after the indentation test. "

The indentation test apparatus of the present invention can surely prevent the apparatus from becoming dirty due to the indentation test.

The figure which shows the indentation test apparatus which concerns on embodiment of this invention. Sectional view of FIG. The figure which shows the connection structure of the housing and the outer cylinder part of the apparatus of FIG. The figure which shows the structure which the contact detection sensor was combined with the structure of FIG. The figure which shows the structure which attached the inner cover to the structure of FIG. The figure which shows the conventional indentation test apparatus Schematic diagram of conventional indentation test equipment The figure which shows the use state of the conventional indentation test equipment. The figure which shows the conventional indentation test apparatus which has another structure.

As shown in FIGS. 1 and 2 (cross-sectional view of FIG. 1), the indentation test apparatus of the present invention includes a housing 10 in which an indenter 50 projects from an end face, an outer cylinder portion 61 that covers the outer periphery of the housing 10, and an outer cylinder portion 61. It includes a sensor holding portion 62 that is attached to the outer cylinder portion 61 and holds the contact detection sensor 221 and a cap-shaped cover 64 that covers the periphery excluding the tip portion of the indenter 50 and the contact detection sensor 221. The cover 64 is composed of an inner cover 642 and an outer cover 641.

FIG. 3 shows a coupling state between the housing 10 and the outer cylinder portion 61. Similar to the device of FIG. 7, the housing 10 accommodates a calculation unit 40, a force sensor 30, a mechanical coupling portion between the force sensor 30 and the indenter 50, and the like. The indenter 50 protrudes greatly from the housing 10, which is different from the configuration of FIG. 7. The outer cylinder portion 61 is provided to secure a mounting place for the contact detection sensor 221.

FIG. 4 shows a state in which the sensor holding portion 62 holding the contact detection sensor 221 is coupled to the outer cylinder portion 61 with respect to the structure of FIG.
The tip of the contact detection sensor 221 supported by the housing 10 via the sensor holding portion 62 and the outer cylinder portion 61 is located closer to the housing 10 than the tip of the indenter 50 protruding from the housing 10. be. The difference in the distance between the tip of the indenter 50 and the tip of the contact detection sensor 221 corresponds to the distance difference between the indenter 50 of the device of FIG. 7 and the end of the housing 11.
The sensor holding portion 62 is provided with an engaging portion 621 to which the inner cover 642 is mounted, and a concave ring portion 622 and a convex portion 623 to which the outer cover 641 is engaged.

FIG. 5 shows a state in which the inner cover 642 is attached to the structure of FIG.
The inner cover 642 has a cap shape and is made of a thin and soft material. The top surface of the cap has a hole through which each of the indenter 50 and the contact detection sensor 221 passes, and the end of the inner cover 642 through which the indenter 50 and the contact detection sensor 221 pass is engaged with the sensor holding portion 62. It is attached to the joint portion 621.
Most of the foreign matter that enters the inside of the inner cover 642 from between the indenter 50 and the contact detection sensor 221 is blocked by the inner cover 642.
Further, even when the inner cover 642 touches the indenter 50 or the contact detection sensor 221, the inner cover 642 made of a soft material does not affect the characteristics of the indenter 50 or the contact detection sensor 221.

FIG. 2 shows a state in which the outer cover 641 is attached to the structure of FIG.
The outer cover 641 has a cap shape and is made of a hard material. On the top surface of the cap, one large hole through which all of the indenter 50 and the contact detection sensor 221 pass is formed.
Further, the inner surface of the side wall of the cap-shaped outer cover 641 is provided with a ridge ring that fits into the concave ring portion 622 of the sensor holding portion 62 and a concave portion that engages with the convex portion 623 of the sensor holding portion 62. The outer cover 641 is attached to the sensor holding portion 62 so that they engage.
The outer cover 641 attached to the sensor holding portion 62 protects the inner cover 642 and cooperates with the inner cover 642 to prevent foreign matter from entering the inside.

The operator who operates this device grips the outer cylinder portion 61 of the indentation test device, and pushes the indenter 50 into the subject until the contact detection sensor 221 detects the subject. At this time, the pushing load acting on the indenter 50 at the time when the contact detection sensor 221 detects the subject is detected by the force sensor 30, and the Young's modulus E of the subject is calculated based on the detection load.
After the indentation test, the operator removes the outer cover 641 and the inner cover 642 from the sensor holding portion 62, and the tip portion not covered by the indenter 50 and the cover 64 of the contact detection sensor 221 and the removed outer cover 641 and inner cover. Clean 642.
As described above, this indentation test device can surely prevent foreign matter from entering the device, and can easily perform cleaning after the test.
Although the case where the cover 64 is composed of the inner cover 642 and the outer cover 641 has been described here, only the outer cover 641 may be used, or only the inner cover 642 may be used.

The indentation test apparatus of the present invention can prevent a part of a subject or stains attached to the subject from entering the apparatus, and handles food fields, medical fields, and materials that require measurement of softness. It can be widely used in a wide range of fields such as fields.

10 Housing 11 End 30 Force sensor 40 Calculation part 50 Indenter 60 Grip part 61 Outer cylinder part 62 Sensor holding part 64 Cover 221 Contact detection sensor 621 Engagement part 622 Concave ring part 623 Convex part 641 Outer cover 642 Inner cover

Claims (3)

The indenter pushed into the subject and
A force sensor that is mechanically coupled to the indenter and detects the force acting on the indenter,
The mechanical coupling portion of the indenter with the force sensor, the housing in which the force sensor is arranged, and the housing.
A plurality of pin-shaped contact detection sensors supported by the housing so as to surround the indenter, and
The indenter mechanically coupled to the force sensor has at least a tip portion outside the housing, and the tip portion of the indenter is the tip of the contact detection sensor when viewed from the housing. It is an indentation test device located at a position farther than the part by a predetermined distance.
An indentation test device in which the periphery excluding the indenter and the tip portions of a plurality of contact detection sensors is covered with a cover member. The indentation test apparatus according to claim 1.
An indentation test device in which the cover member includes an inner cover having a plurality of through holes through which the contact detection sensor and the indenter are individually inserted, and an outer cover that covers the inner cover from the outside. The indentation test apparatus according to claim 1 or 2.
The plurality of contact detection sensors are fixed to a sensor holding portion supported by the housing, and the plurality of contact detection sensors are fixed to the sensor holding portion.
An indentation test device in which the cover member is detachably attached to the sensor holding portion.

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