DE29620422U1 - Optoelectronic sensor with holding devices integrated in a basic housing body - Google Patents

Description

Optoelectronic sensors are used in a wide variety of designs for a wide range of applications. These sensors detect changes that affect the active optical radiation field from the outside. In order to generate this optical field, the transmitted radiation from a radiation source is guided by optical means via a so-called influence zone to the radiation receiver of the optoelectronic sensor. Depending on the task of the optoelectronic sensor, it is necessary to dimension the influence zone in terms of size, type or quality. Three basic systems of optoelectronic sensors have essentially been developed. The most important systems are the one-way systems, the reflection systems and the button systems.

The one-way system consists of a spatially separated transmitter on one side and a receiver on the opposite side of the monitoring path. In the reflection system, however, the transmitter and receiver are combined into one unit. At the opposite end of the monitoring path, a retroreflector is required, which reflects the emitted radiation back into itself, i.e. back into the sensor. If an object to be detected is located within the optical beam influence area, the optical beam flow from the transmitter to the receiver is attenuated or even completely interrupted.

In the case of optoelectronic scanning systems, however, the optical radiation from the transmitter is remitted at the object to be detected and this remitted radiation is received by the optical receiver.

All three optoelectronic sensors therefore generally require a radiation source, a radiation receiver, optical elements for designing and shaping the radiation path, the processing of the power supply unit and

an evaluation unit, including any setting, operating and connection elements, is available.

The multitude of these mostly discrete components, i.e. the radiation source, the optoelectronic receiver, the optical and electronic components as well as the operating elements must be positioned and fixed precisely to one another within a housing. In this case, a high degree of protection must often be ensured by the housing in order to ensure that the sensor can be used even under difficult operating conditions (dust, moisture, shock and vibration). The assembly steps required for this are often very time-consuming and costly and require additional space for the size of the sensor.

The object of the invention is to create a sensor of the type mentioned at the beginning, which enables economical manufacture, simple construction and compact design. This requires in particular that the assembly and adjustment _- especially of the optical and optoelectronic components to each other and to the housing - is carried out without problems. At the same time, the resistance of these sensors to environmental influences such as moisture, dust or mechanical stress should be achieved using simple means.

To solve this problem, the invention provides that a housing base body is provided which comprises both housing walls and receiving devices for optoelectronic, electrical, optical and/or mechanical components. There is thus created an optoelectronic sensor with a housing in which a radiation source and/or an optoelectronic receiver, optical components for influencing the beam, electronic circuit components and electrical and/or mechanical setting, operating or contacting elements are arranged, the sensor having a housing which is arranged within a housing

base body contains mounting devices for the optoelectronic, electrical, optical and/or mechanical components that are firmly connected to it and precisely positioned relative to one another.
5

This means that the optical and optoelectronic components as well as the electronic connection and control elements can be inserted into the receiving and holding functions integrated in the housing without great effort in terms of fastening and adjustment. For this purpose, in the housing according to the invention, which has a high degree of rigidity despite low wall thicknesses due to the preferably provided stiffening longitudinal and/or transverse ribs, all receiving elements and holding devices, including the optics tube, are already integrated in the injection-molded plastic housing in addition to the outer housing wall.

The housing according to the invention allows the individual components, such as the transmitting and receiving components, the optical lenses, filters, mirrors, apertures, as well as the setting and operating elements, the corresponding circuit boards and even the variable connection technology via cable connectors or the like, to be inserted into the housing effortlessly and in a precisely positioned manner.

The adjustment effort previously required for each sensor is now largely shifted to the one-time production of the injection molding tool.

The snap-in technology used at the same time means that conventional connection techniques such as gluing, screwing, flanging, riveting and the like can largely be replaced. This not only significantly reduces assembly time, but also ensures environmentally friendly processing, which even makes it easier to recycle the sensors.

The invention is described in more detail below with reference to Figure 1. The housing (1) shown in section has the following outer side surfaces:

Light exit surface (2), head-side housing surface (3), rear housing surface (4) and foot-side connection surface (5)

The light exit surface (2) is closed in the area of the light exit (6) or the light entry (7) with a cover plate (8) that is permeable to the radiation range used and is tightly connected to the housing (1) by means of ultrasonic welding. Inside the housing (1), behind the cover plate (8), the optical transmission tube (9) and the optical reception tube (10) are integrated in the housing according to the invention. The optical assembly (11) is located between the optical tubes (9, 10) and the cover plate (8). This optical assembly (11) is also inserted into injection-molded locking devices provided in the plastic housing.

(12) positioned, received. The optical transmission tube (9) is equipped at the rear with the optical transmitter (13), which is connected to the housing (1) by means of a corresponding snap-in grid. In the optical reception tube (10) there is a holder for the deflection mirror (14). On the lower side of the optical reception tube there is a clamp holder into which a filter foil and/or an optical aperture (15) can be inserted. Arranged after this in the direction of the optical radiation there is an electrical circuit board (16) onto which the photoelectric converter (17) is contacted. This circuit board (16) is also positioned and received by the setting latches provided in the housing (1). The circuit board (18), on which the electrical evaluation and supply circuit is located, is snapped into the housing parallel to the display plane without additional adhesive or screw connections. On the head-side housing surface (3) there is also an ultrasonic

An optical cover plate (19) is welded tightly to the housing (1) and allows the radiation from the display diode (20) to pass through so that it is visible to the eye. In the rear housing surface (4) there are sealed, rotating bushings (21) to operate the electrical operating and setting elements located behind them. In the base connection surface (5) there is a receiving device that can accommodate either a plug connector (22) or a cable bushing (not shown). In the plane of the drawing, this housing is closed on both sides with flat covers, also made of plastic (not shown in detail in this figure), e.g. by means of ultrasonic welding.

List of reference symbols

1 Housing base

2 Light exit surface

3 Head-side housing surface

4 Rear housing surface

5 Foot-side connection surface

6 Light emission

7 Light entry

8 Permeable cover plate

9 Optical transmission tube

10 Optical receiving tube

11 Optical assembly

12 setting traps

13 Optical transmitter

14 Deflecting mirrors

15 Optical aperture and/or filter foil

16 Electrical circuit board

17 Photoelectric converter

18 Circuit board

19 Optical cover plate 2 0 Indicator diode

21 Rotatable bushings

22 connectors

Claims (9)

1· · I Claims 1. Optoelectronic sensor with a housing in which a radiation source and/or an optoelectronic receiver, optical components for influencing the beam, electronic circuit components as well as electrical and/or mechanical setting, operating or contacting elements are arranged, characterized in that the sensor has a housing which, within a housing base body, contains receiving devices for the optoelectronic, electrical, optical and/or mechanical components which are firmly connected to the housing base body and are precisely positioned relative to one another. 2. Optoelectronic sensor according to claim 1, characterized in that the housing base body including the receiving devices is injection-molded from plastic that is impermeable to the optical radiation range used, in particular is injection-molded in one piece. 3. Optoelectronic sensor according to claim 1 or 2, characterized in that the housing is tightly closed with ultrasonically welded covers. 4. Optoelectronic sensor according to one of the preceding claims, characterized in that the housing base body is designed to be at least substantially torsion-resistant and is provided with stabilizing longitudinal and/or transverse ribs. 5. Optoelectronic sensor according to one of the preceding claims, characterized in that the housing base is designed in one piece with an optical transmitting and/or receiving tube. 6. Optoelectronic sensor according to one of the preceding claims, characterized in that the fastening of the components to be inserted into the housing base body is realized by means of snap-in technology. 7. Optoelectronic sensor according to one of the preceding claims, characterized in that receiving devices designed as snap-on connection elements are formed in one piece with the housing base body. 8. Optoelectronic sensor according to one of the preceding claims, characterized in that the housing can be adapted to different connection technologies, in particular to cable connectors. 9. Optoelectronic sensor according to one of the preceding claims, characterized in that in order to achieve good recyclability, at least the housing base body and the receiving devices are made of a uniform material.