Photoelectric sensor with multiple optical axes

Abstract

Photoelectric sensor (100) with multiple optical axes comprising a light projector (110) and a light receiver (120), each having an outer shape defined by a housing (1), comprising: an outer housing (10) with an opening (14) in a front surface of the outer housing (10), a translucent panel (15) which is designed to close the opening (14), and a pressure element (20) which is designed to press the translucent plate (15) against the outer housing (10), wherein the outer housing (10) has a pair of side plates with respective inner surfaces on which support parts (11b) are provided for supporting the respective side edge parts of the translucent plate (15), wherein the pair of side plates each has projecting parts (11c), each of which is provided on an end part in which the opening (14) is formed, and each extends towards an end part of the other of the pair of side plates, and wherein the pressure element (20) has first projection parts (21) and second projection parts (22) which are opposite each other in a thickness direction of the translucent plate (15), and is arranged to press the translucent plate (15) against the support parts (11b) by being attached to the projecting parts (11c) such that the projecting parts (11c) are each inserted between a corresponding first projection part (21) and a corresponding second projection part (22), characterized in that a first projection (11d) and a recess (21a), with which the first projection (11d) is to engage, are each provided on a surface A and a surface B or each on a surface B and a surface A, wherein the area A is an area of ​​each of the projecting parts (11c), wherein this area is opposite a corresponding of the first projecting parts (21) or a corresponding of the second projecting parts (22), and wherein area B is an area of ​​one of the first projecting parts (21) or of one of the second projecting parts (22), wherein this area is opposite a corresponding projecting part (11c).

Description

TECHNICAL FIELD

[0001] The present invention relates to a photoelectric sensor with multiple optical axes, comprising a light projector and a light receiver, each having an external shape defined by a casing including an outer casing having an opening in a front surface of the outer casing, a light-transmitting plate configured to close the opening, and a pressing member configured to press the light-transmitting plate against the outer casing. TECHNICAL BACKGROUND

[0002] JP 4628402 B2 discloses a photoelectric sensor comprising: a main body casing; a light-transmitting plate; and a first pressing member for pressing and fixing the light-transmitting plate to the main body casing. According to the photoelectric sensor, the main body casing is provided with: (i) a first transmission opening for transmitting light therethrough; (ii) a pair of first mounting surfaces provided to engage the first transmission opening; (iii) a pair of first projection portions protruding from the main body casing relative to the pair of first mounting surfaces; and (iv) a pair of engagement holes provided between the first mounting surfaces and the corresponding first projection portions. The light-transmitting plate is attached to the first mounting surfaces to close the first transmission opening.The pressing member is attached to the pair of engagement holes so as to press one side of the translucent plate, which side is opposite to a side opposite to the first attachment surfaces.

[0003] DE 20 2011 051 295 U1 discloses a light grid with light emitters and light receivers, which in pairs form individual, parallel-aligned light barriers. The light emitters and light receivers are arranged in at least one elongated aluminum housing and are each assigned to optical modules. The housing has a front window through which the light beams from the light barriers pass, and the housing can be secured to a mounting surface via at least one holder. An optical module comprises a one-piece multiple lens with several lenses arranged adjacently in the longitudinal direction of the housing and connected to one another; a one-piece tube body with several tubes arranged adjacently in the longitudinal direction of the housing; and a one-piece diaphragm carrier with several diaphragm openings arranged adjacently in the longitudinal direction of the housing, wherein a tube, a lens, and a diaphragm opening are each aligned with one another.

[0004] US 2018 / 0 017 434 A1 discloses a light projector and a light receiver, each comprising a housing body, a light transmission plate closing an opening in a front surface of the housing body, and a pair of caps closing openings in end surfaces of the housing body. The housing body includes first supports supporting side edges of the light transmission plate, the caps each include second supports supporting ends of the light transmission plate, and the light transmission plate is supported by the first supports and the second supports with an elastic member interposed therebetween. First engagement units are provided in the cap and the light transmission plate, respectively, which engage with each other to limit longitudinal inward displacements of the ends of the light transmission plate supported by the second supports.

[0005] DE 44 38 798 A1 discloses a light barrier with transmitter-receiver components as optics and optionally an optics cover, wherein the optics or optics cover is at least partially provided with impact protection.

[0006] DE 100 61 893 A1 discloses a housing for accommodating a measuring device with at least two housing parts that can be positively connected to one another via a fastening device, wherein at least one housing part has an at least partially transparent viewing window, wherein an insertion device is provided which has an opening gap provided in the housing and an insertion pocket for receiving a label. OVERVIEW OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, according to the photoelectric sensor disclosed in Patent Document 1, in a case where the pressure element is attached, the light-transmitting plate must be pressed with increased force at times. Unfortunately, this requires increased effort to mount the photoelectric sensor.

[0008] An object of one aspect of the present invention is to realize a photoelectric sensor with multiple optical axes, which can be mounted with reduced effort. MEANS FOR SOLVING THE TASK

[0009] To achieve the object, a photoelectric sensor with multiple optical axes in accordance with one aspect of the present invention is a photoelectric sensor having the features of claim 1. A photoelectric sensor according to another aspect of the invention has the features of claim 2. A photoelectric sensor according to another aspect of the invention has the features of claim 6. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0010] With one aspect of the present invention, it is possible to realize a photoelectric sensor with multiple optical axes, which can be mounted with reduced effort. SHORT DESCRIPTION OF THE CHARACTERS Fig. 1 is a development view showing a configuration of a housing according to Embodiment 1. Fig. 2 is a view showing an overview of a photoelectric sensor with multiple optical axes in accordance with Fig. 1 shows. Fig. 3 is a view schematically showing the housing according to Embodiment 1. Fig. 4 is a partial cross-sectional view showing a structure of the housing according to Embodiment 1. Fig. 5 is a partial cross-sectional view showing a structure of a housing in accordance with a variation 1. Fig. 6 is a partial cross-sectional view showing a structure of a housing in accordance with a variation 2. Fig. 7 is a partial cross-sectional view showing a structure of a housing in accordance with a variation 3. EMBODIMENTS OF THE INVENTION Embodiment 1

[0011] The present description will discuss an embodiment according to one aspect of the present invention (hereinafter also referred to as "present embodiment") with reference to the figures. It should be noted that the present embodiment described below is merely an example of the present invention in all aspects. It should be understood that various modifications and variations can be made without departing from the scope of the invention. In other words, in implementing the present invention, a specific configuration corresponding to the embodiment can be appropriately used. § 1 Application example

[0012] An example in which the present invention is applied will first be described with reference to the Fig. 2 and Fig. 3 described. Fig. 2 is a view showing an overview of a multi-optical axis photoelectric sensor 100 according to the present embodiment. As shown in Fig. As shown in Figure 2, the multi-optical axis photoelectric sensor 100 includes a light projector 110 and a light receiver 120 that are disposed to oppose each other across a predetermined detection region. As shown in Fig. 2, a plurality of optical axes are set between the light projector 110 and the light receiver 120 so that the photoelectric sensor 100 with a plurality of optical axes detects an object depending on whether light enters or is blocked on these optical axes.

[0013] Fig. 3 is a view schematically showing a housing 1. The housing 1 is used as a housing of the light projector 110 and the light receiver 120, respectively. The housing 1 includes: a main body housing 11; cap members 12 and 13; a light-transmitting plate 15; and a pressing member 20 (see Fig. 1). In Fig. 3, the pressure element 20 can be omitted.

[0014] As in Fig. 3, in the housing 1, the main body housing 11 and the cap members 12 and 13 form an outer housing 10. Specifically, the outer housing 10 is configured such that the cap members 12 and 13 fit into respective longitudinal end portions of the cylindrical main body housing 11 having a rectangular cross section.

[0015] The outer casing 10 has an opening 14 in one surface of the outer casing 10. The opening 14 is closed by the translucent plate 15. The translucent plate 15 is pressed against the casing 1 by the pressing element 20. In the following description, the surface of the casing 1 having the opening 14 therein is referred to as the "front surface." The direction from the interior of the casing 1 toward the front surface is referred to as the "front direction" or "front side."

[0016] As in Fig. As shown in Figure 3, the opening 14 may be formed throughout the entire main body casing 11 and the cap members 12 and 13. However, the opening 14 may be formed only in the main body casing 11. That is, the opening 14 must be formed at least only in the main body casing 11.

[0017] The multi-optical-axis photoelectric sensor 100 can be described as follows. The multi-optical-axis photoelectric sensor 100 is configured such that the respective external shapes of the light projector 110 and the light receiver 120 are each defined by a housing 1 (which includes: an outer casing 10 having an opening 14 in a front surface thereof; a light-transmitting plate 15 provided to close the opening 14; and a pressing member 20 provided to press the light-transmitting plate 15 against the housing 1). § 2 Design example

[0018] An example of the design of the housing 1 is described below with reference to the Fig. 1 to 4. In Fig. 1 and Fig. 4, a width direction of the housing 1 is defined as an x-direction, a longitudinal direction is defined as a y-direction, and front-back directions are defined as z-directions. Specifically, the front direction of the housing 1 is defined as a positive z-direction.

[0019] Fig. Figure 1 is a development view showing the configuration of the housing 1 according to the present embodiment. As described above, the housing 1 is configured so that the cap members 12 and 13 fit into the respective longitudinal end portions of the main body housing 11.

[0020] An optical element 16 is contained in the housing 1. In a case where the housing 1 is used as a light projector 110, the optical element 16 is a light-emitting element. In a case where the housing 1 is used as a light receiver 120, the optical element 16 is a light-receiving element. At least one of the cap members 12 and 13 is provided with a connector (not shown) for supplying electrical power to the optical element 16 or for extracting a signal from the optical element 16.

[0021] The housing 1 further includes an adhesive tape 17 (adhesive material). The translucent plate 15 is provided to close the opening from a front side of the adhesive tape 17. The pressing element 20 is attached to the front side of the translucent plate 15. The specific positions and the like of the adhesive tape 17 and the pressing element 20 will be described later.

[0022] The length of the main body casing 11 varies depending on the form to which the multi-optical-axis photoelectric sensor 100 is applied. According to the multi-optical-axis photoelectric sensor 100, the main body casing 11 can have any length by cutting the adhesive tape 17 (having a sufficient length) according to the length of the main body casing 11.

[0023] Fig. Fig. 4 is a partial cross-sectional view showing a structure of the housing 1. In particular, Fig. 4 is a cross-sectional view of the housing 1 taken on a surface that is (i) perpendicular to the longitudinal direction of the housing 1 and (ii) includes the main body housing 11. As in Fig. As shown in Fig. 4, the main body casing 11 has a pair of side plates 11a on respective sides in the width direction. On respective inner surfaces of the side plates 11a, corresponding support parts 11b are provided for supporting both end edge sides of the translucent plate 15. The cap members 12 and 13 are also provided with support parts (not shown) continuous with the support parts 11b. According to the present embodiment, the adhesive tape 17 is provided on front surfaces of the support parts 11b. The adhesive tape 17 causes the translucent plate 15 to adhere to the support parts 11b.

[0024] Respective end portions of the side plates 11a, at which the opening 14 is provided, are provided with corresponding protruding portions 11c, each extending toward the end portion of the other side plate 11a. The pressure element 20 is attached to the protruding portions 11c.

[0025] Specifically, the housing 1 is configured such that the pressing member 20 includes first protrusion portions 21 and second protrusion portions 22. The first protrusion portions 21 and the second protrusion portions 22 are opposed to each other in directions in which the thickness of the light-transmitting plate extends. The first protrusion portions 21 and the second protrusion portions 22 are provided substantially over the entire length of the main body housing 11. The first protrusion portions 21 are positioned further forward than the second protrusion portions 22, while the pressing member 20 is attached to the protrusion portions 11c. The pressing member 20 presses the light-transmitting plate 15 against the support portions 11b by attaching the protrusion portions 11c such that the protrusion portions 11c are sandwiched between the first protrusion portions 21 and the second protrusion portions 22.Specifically, in the present embodiment, the pressing element 20 is attached to the protruding portions 11c by moving it parallel to the front surface of the housing 1. Thus, in a case where the pressing element 20 is attached, it is not necessary to press the light-transmitting plate 15 with a force greater than or equal to a pressing force applied by the attached pressing element 20. This reduces the labor required for assembling the multi-optical-axis photoelectric sensor 100 having the housing 1.

[0026] Because the translucent plate 15 is pressed by the pressing member 20, a gap between the translucent plate 15 and the support parts 11b is small. This limits the ingress of liquid, such as oil, into the housing 1. Specifically, according to the housing 1 of the present embodiment, a space between the translucent plate 15 and the support parts 11b is sealed by the adhesive tape 17. This further limits the ingress of liquid compared to a housing that does not have the adhesive tape 17.

[0027] In the present embodiment, a distance between respective tips of the pair of protruding parts 11c is larger than a width of the translucent plate 15. Thus, in a case where the housing 1 is assembled, it is possible to place the translucent plate 15 on the support parts 11b from the front side of the outer housing 10.

[0028] A first projection 11d is provided on a surface of each of the protruding portions 11c, which surface is opposite to the corresponding first projection portion 21. A recess 21a is provided on a surface of each of the first projection portions 21, which surface is opposite to the corresponding protruding portion 11c, such that the corresponding first projection 11d engages the recess 21a. The recess 21a is provided to correspond to the position of the first projection 11d when the pressing member 20 is properly attached to the protruding portion 11c.

[0029] Thus, in a case where the pressure element 20 is not properly attached to the protruding part 11c, the first protrusion part 21 protrudes from the protruding part 11c. Thus, in a case where the pressure element 20 is not properly attached to the protruding part 11c, it is easy to visually monitor that the pressure element 20 is not properly attached to the protruding part 11c.

[0030] It should be noted that according to the housing 1 of the present embodiment, the first projection portions 21 may be provided with the first projections 11d, and the projecting portions 11c may be provided with the recesses 21a. Furthermore, (i) each first projection 11d may be provided on a surface of the corresponding projecting portion 11c, which surface is opposite to the corresponding second projection portion 22, and (ii) each recess 21a may be provided on a surface of the corresponding second projection portion 22, which surface is opposite to the corresponding projecting portion 11c.That is, the housing 1 according to the present embodiment only needs to be configured such that the first projection 11d and the recess 21a with which the first projection 11d engages are provided on the following surface A and the following surface B, respectively, or are provided on the following surface B and the following surface A, respectively. The surface A is a surface of the protruding part 11c, which surface is opposite to the first protruding part 21 or the second protruding part 22. The surface B is a surface of the first protruding part 21 or the second protruding part 22, which surfaces are opposite to the protruding part 11c. With the housing 1, it is possible to properly determine a position at which the pressing element 20 is attached to the protruding parts 11c.

[0031] Furthermore, each of the side plates 11a has an engagement part 11e which engages with the corresponding first projection part 21 (an end part of the pressure element) and which is provided farther away from the light-transmitting plate 15 than the corresponding projecting part 11c. As shown in Fig. Specifically, as shown in Fig. 4, the engagement part 11e is formed obliquely so as to rise in a front direction from the protruding part 11c, increasingly closer to a widthwise center of the main body case 11c. A tip part of the first protrusion part 21 is also formed obliquely so that, as the pressing member 20 is attached to the protruding part 11c, the tip part rises in a front direction, increasingly closer to the widthwise center of the main body case 11. This reduces a risk that the first protrusion part 21 rises upward from the protruding part 11c, even in a case where the pressing member 20 is properly attached to the protruding part 11c, the pressing member 20 is deformed so that a distance between the first protrusion part 21 and the second protrusion part 22 is increased. § 3 Variations

[0032] Fig. Fig. 5 is a partial cross-sectional view showing a structure of a housing 1A according to a variation 1. The housing 1A differs from the housing 1 in that the housing 1A includes a pressing member 20A instead of a pressing member 20. The pressing member 20A differs from the pressing member 20 in that the pressing member 20A includes two second projections 21b, each provided on a surface of the corresponding first projection part 21, which surface opposes a corresponding projecting part 11c.

[0033] According to the pressing element 20A, the first protrusion portions 21 each contact the corresponding protruding portion 11c only at the second protrusion 21b. Thus, in the process of attaching the pressing element 20A to the protruding portions 11c, a frictional force is generated between the first protrusion portions 21 and the protruding portions 11c, which is smaller than a frictional force generated in the process of attaching the pressing element 20 to the protruding portions 11c. In other words, the force required to attach the pressing element 20A to the protruding portions 11c is smaller than the force required to attach the pressing element 20 to the protruding portions 11c. A multi-optical-axis photoelectric sensor having the housing 1A is thus easier to assemble than a multi-optical-axis photoelectric sensor 100 having the housing 1.

[0034] The second protrusions 21b are each provided on a surface opposite to a surface of the corresponding protruding part 11c, which surface is provided with the first protrusion 11d. In addition, the second protrusions 21b are provided further out in a width direction than the first protrusions 11d while the pressing member 20A is attached to the protruding parts 11c. This causes the second protrusion 21b to be gripped by the corresponding first protrusion 11d in a case where the pressing member 20A moves in a direction of detaching from the protruding part 11c. Thus, inadvertent detachment of the pressing member 20A from the protruding part 11c is restricted.

[0035] In Variation 1, it is only necessary that the second projection 21b be provided on a surface of the first projection portion 21 or the second projection portion 22, which surface is opposite to a surface of the projecting portion 11c, which surface includes the first projection 11d. If the first projection 11d is provided on the surface of the projecting portion 11c, which surface is opposite to the second projection portion 22, then the second projection 21b is provided on the surface of the second projection portion 22, which surface is opposite to the surface of the projecting portion 11c on which the first projection 11d is provided.

[0036] Fig. Fig. 6 is a partial cross-sectional view showing a structure of a housing 1B according to a variation 2. The housing 1B differs from the housing 1 in that the housing 1B has elastic members 18 between the pressure member 20 and the light-transmitting plate 15. As shown in Fig. As shown in Figure 6, the elastic elements 18 each have a rectangular cross-sectional shape. In particular, the elastic elements 18 are, for example, flat rubber pieces.

[0037] According to the housing 1B, the pressure element 20 presses the translucent plate 15 with the elastic elements 18 therebetween. According to the housing 1B, the translucent plate 15 is thus pressed more strongly due to the elasticity of the elastic elements 18. As a result, the adhesive element 17 is pressed more strongly. This reduces the risk of exposing the optical element 16 (see Fig. 1) to liquids such as oil. Due to a space between the pressure element 20 and the translucent plate 15, which is sealed by the elastic elements 18, the risk of the adhesive tape 17 being exposed to liquids is also reduced.

[0038] Fig. Fig. 7 is a partial cross-sectional view showing a structure of a housing 1C according to a variation 3. As in Fig.As shown in Fig. 7, the housing 1C differs from the housing 1B in that (i) the housing 1C has elastic elements 18C instead of the elastic elements 18, and (ii) the housing 1C has a pressing element 20C instead of the pressing element 20. The elastic elements 18C differ from the elastic elements 18 in that the shape of a cross section of each elastic element 18C is circular instead of rectangular. The pressing element 20C differs from the pressing element 20 in that the pressing element 20C has grooves 23 into which the respective elastic elements 18C can be fitted.

[0039] The depth of each groove 23 is greater than a radius of the cross section of the respective corresponding elastic member 18C and is smaller than a diameter of the cross section of the elastic member 18C. The cross section of the groove 23 has a shape corresponding to the cross section of the elastic member 18C. That is, (i) the width of the groove 23 at a surface of the pressing member 20C is smaller than the diameter of the elastic member 18C, and (ii) the groove 23 has a part falling within the pressing member 20C, the width of the part being substantially equal to a diameter of the elastic member 18C. Thus, the elastic member 18C fitted in the groove 23 is unlikely to detach from the groove 23 due to gravity or the like. Note that the elastic member 18C has elasticity.Thus, by changing the shape of the elastic member 18C by pressure, it is possible to fit the elastic member 18C into the groove 23 having the width narrower than a diameter of the elastic member 18C which has not been changed in shape.

[0040] According to the housing 1C, the pressing element 20C presses the light-transmitting plate 15 with the elastic elements 18C therebetween. With the housing 1C, the following effect can be obtained in addition to the effect obtained with the housing 1B. That is, by fitting the elastic elements 18C into the respective grooves 23 in advance when assembling the housing 1C, it is no longer necessary to consider the positions of the elastic elements 18C when attaching the pressing element 20C to the protruding parts 11c. A multi-optical-axis photoelectric sensor having the housing 1C is thus easier to assemble compared to a multi-optical-axis photoelectric sensor having the housing 1B.

[0041] The present invention is not limited to the embodiments, but can be modified by a person skilled in the art within the scope of the patent claims. The present invention also includes within its technical scope any embodiments that can be derived by combining the technical means disclosed in the various embodiments. Summary

[0042] As described, a multi-optical-axis photoelectric sensor according to one aspect of the present invention is a multi-optical-axis photoelectric sensor comprising a light projector and a light receiver, each having an external shape defined by a housing, comprising an outer housing having an opening in a front surface of the outer housing, a light-transmitting plate configured to close the opening, and a pressing member configured to press the light-transmitting plate against the outer housing, wherein the outer housing has a pair of side plates with respective inner surfaces on which support portions for supporting the respective side edge portions of the light-transmitting plate are provided, wherein the pair of side plates each have protruding portions, each of which is provided at an end portion at which the opening is formed,and each extends toward one end portion of the other of the pair of side plates, and wherein the pressing member has first protruding portions and second protruding portions opposite each other in the thickness direction of the light-transmitting plate, and is configured to press the light-transmitting plate against the supporting portions by being attached to the protruding portions such that the protruding portions are each sandwiched between a corresponding one of the first protruding portions and a corresponding one of the second protruding portions.

[0043] According to the embodiment, the translucent plate is supported by the support portions each provided on the inner surface of the corresponding side plate of the outer casing so as to extend toward the end portion of the other side plate. The pressure element is attached to the end portions of the outer casing such that the projecting portions are sandwiched between the corresponding first projection portion and the corresponding second projection portion.

[0044] When the pressure element is attached to the protruding parts, the pressure element presses the translucent plate with proper pressure, which is supported by the support parts provided on the inner surfaces of the outer casing. This eliminates the need to press the translucent plate with excessive pressure when attaching the pressure element. This reduces the effort required to assemble the multi-optical-axis photoelectric sensor.

[0045] The multi-optical axis photoelectric sensor in accordance with one aspect of the present invention is configured such that a first projection and a recess with which the first projection is to be engaged are provided on a surface A and a surface B, respectively, or on a surface B and a surface A, respectively, wherein the surface A is a surface of each of the projecting parts, this surface being opposite to a corresponding one of the first projecting parts or a corresponding one of the second projecting parts, and wherein the surface B is a surface of one of the first projecting parts or one of the second projecting parts, this surface being opposite to a corresponding one of the projecting parts.

[0046] According to the embodiment, when the pressure element is attached to the protruding parts, the first projections engage with the corresponding recesses. This makes it possible to properly determine the positions at which the pressure element is attached to the protruding part.

[0047] The multi-optical-axis photoelectric sensor according to one aspect of the present invention is configured such that: a first projection is provided on a surface C that is a surface of each of the projecting parts, this surface being opposite to a corresponding one of the first projection parts or a corresponding one of the second projection parts; and a second projection is provided on a surface of the corresponding one of the first projection parts or the corresponding one of the second projection parts, this surface being opposite to the surface C.

[0048] According to the configuration, the area of ​​a region where the protruding portions and the pressure element are in contact with each other is small during the process of attaching the pressure element to the protruding portions. This results in a small frictional force between the protruding portions and the pressure element. Thus, the force required to press the pressure element against the protruding portions is small. This further reduces the complexity of assembling the multi-optical-axis photoelectric sensor.

[0049] The multi-optical axis photoelectric sensor in accordance with one aspect of the present invention is configured such that the pair of side plates of the outer casing each has an engaging part configured to be engaged with a corresponding end part of the pressing member and provided to be farther away from the light-transmitting plate than a corresponding one of the projecting parts.

[0050] According to this embodiment, the end portion of the protruding portion of the pressure element, which end portion is located on the side farther from the translucent plate, engages with the engagement portion. This reduces the risk that the pressure element will lift off the protruding portions due to deformation of the pressure element after the pressure element is attached to the protruding portions.

[0051] The photoelectric sensor with multiple optical axes in accordance with one aspect of the present invention is configured such that the pressing member is configured to press the light-transmitting plate with an elastic member therebetween.

[0052] According to this embodiment, the translucent plate is pressed more strongly due to the elasticity of the elastic element.

[0053] The multi-optical axis photoelectric sensor in accordance with one aspect of the present invention further includes an adhesive material that causes the light-transmitting plate to adhere to the support members.

[0054] According to this embodiment, the interior of the housing is sealed when the adhesive material is pressed by the pressure force of the pressure element. This limits, for example, the ingress of oil into the housing.

[0055] The multi-optical axis photoelectric sensor according to one aspect of the present invention is configured such that the pressing member is configured to be attached to each of the projecting parts by being moved in a direction parallel to a direction in which the front surface extends.

[0056] According to this configuration, when the pressure element is mounted, it is not necessary to apply a force perpendicular to the front surface. This reduces the effort required to mount the multi-optical-axis photoelectric sensor. LIST OF REFERENCE SYMBOLS

[0055] 1, 1A, 1B, 1C: Housing 10: Outer casing 11b: Support part 11c: protruding part 11d: first lead 14: Opening 15: translucent plate 17: Adhesive tape (adhesive material) 18, 18C: elastic element 20: Pressure element 21: first projection part 21a: Recess 22: second projection part 100: photoelectric sensor with multiple optical axes 110: Light projector 120: Light receiver

Claims

[1] Photoelectric sensor (100) with multiple optical axes comprising a light projector (110) and a light receiver (120), each having an outer shape defined by a housing (1), comprising: an outer casing (10) having an opening (14) in a front surface of the outer casing (10), a translucent plate (15) arranged to close the opening (14), and a pressure element (20) arranged to press the translucent plate (15) against the outer casing (10), wherein the outer casing (10) has a pair of side plates with respective inner surfaces, on which support parts (11b) are provided for supporting the respective side edge parts of the translucent plate (15), wherein the pair of side plates each have projecting parts (11c), each of which is provided at an end part at which the opening (14) is formed, and each extending towards an end part of the other of the pair of side plates, and wherein the pressure element (20) has first projection parts (21) and second projection parts (22) which are opposite to each other in a thickness direction of the light-transmitting plate (15), and is arranged to press the light-transmitting plate (15) against the support parts (11b) by being attached to the projecting parts (11c) such that the projecting parts (11c) are each sandwiched between a corresponding one of the first projection parts (21) and a corresponding one of the second projection parts (22), characterized bythat a first projection (11d) and a recess (21a) with which the first projection (11d) is to be engaged are provided on a surface A and a surface B, respectively, or on a surface B and a surface A, wherein the surface A is a surface of each of the projecting parts (11c), which surface is opposite to a corresponding one of the first projecting parts (21) or a corresponding one of the second projecting parts (22), and wherein the surface B is a surface of one of the first projecting parts (21) or one of the second projecting parts (22), this surface being opposite to a corresponding one of the projecting parts (11c). [2] Photoelectric sensor (100) with multiple optical axes comprising a light projector (110) and a light receiver (120), each having an outer shape defined by a housing (1), comprising: an outer casing (10) having an opening (14) in a front surface of the outer casing (10), a translucent plate (15) arranged to close the opening (14), and a pressure element (20) arranged to press the translucent plate (15) against the outer casing (10), wherein the outer casing (10) has a pair of side plates with respective inner surfaces, on which support parts (11b) are provided for supporting the respective side edge parts of the translucent plate (15), wherein the pair of side plates each have projecting parts (11c), each of which is provided at an end part at which the opening (14) is formed, and each extending towards an end part of the other of the pair of side plates, wherein the pressure element (20) has first projection parts (21) and second projection parts (22) which are opposite to each other in a thickness direction of the light-transmitting plate (15), and is arranged to press the light-transmitting plate (15) against the support parts (11b) by being attached to the projecting parts (11c) such that the projecting parts (11c) are each sandwiched between a corresponding one of the first projection parts (21) and a corresponding one of the second projection parts (22), characterized by that a first projection (11d) is provided on a surface C which is a surface of each of the projecting parts (11c), this surface being opposite to a corresponding one of the first projecting parts (21) or a corresponding one of the second projecting parts (22); and wherein a second projection (21b) is provided on a surface of the corresponding one of the first projection parts (21) or the corresponding one of the second projection parts (22), this surface being opposite to the surface C. [3] A multi-optical axis photoelectric sensor (100) according to claim 1 or 2, wherein the pair of side plates of the outer casing (10) each has an engagement part adapted to be engaged with a corresponding end part of the pressing member (20) and provided to be farther away from the light-transmitting plate (15) than a corresponding one of the projecting parts (11c). [4] A multi-optical axis photoelectric sensor (100) according to any one of claims 1 to 3, wherein the pressing member (20) is arranged to press the light-transmitting plate (15) with an elastic member (18) therebetween. [5] A multi-optical axis photoelectric sensor (100) according to any one of claims 1 to 4, further comprising: an adhesive material (17) which causes the translucent plate (15) to stick to the support parts (11b). [6] Photoelectric sensor (100) with multiple optical axes comprising a light projector (110) and a light receiver (120), each having an outer shape defined by a housing (1), comprising: an outer casing (10) having an opening (14) in a front surface of the outer casing (10), a translucent plate (15) arranged to close the opening (14), and a pressure element (20) arranged to press the translucent plate (15) against the outer casing (10), wherein the outer casing (10) has a pair of side plates with respective inner surfaces, on which support parts (11b) are provided for supporting the respective side edge parts of the translucent plate (15), wherein the pair of side plates each have projecting parts (11c), each of which is provided at an end part at which the opening (14) is formed, and each extending towards an end part of the other of the pair of side plates, wherein the pressure element (20) has first projection parts (21) and second projection parts (22) which are opposite to each other in a thickness direction of the light-transmitting plate (15), and is arranged to press the light-transmitting plate (15) against the support parts (11b) by being attached to the projecting parts (11c) such that the projecting parts (11c) are each sandwiched between a corresponding one of the first projection parts (21) and a corresponding one of the second projection parts (22), characterized by that the pressure element (20) is arranged to be attachable to each of the projecting parts (11c) by being moved in a direction parallel to a direction in which the front surface extends.

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