MEASUREMENT SENSOR
The present invention relates to a measurement sensor as described in the preamble of claim 1 , the sensor comprising an elongated sensor part, at the first end of which the electrical connection of the sensor part is located and at the second end of which the sensor end of the sensor part is located, the measurement sensor comprising a first sleeve part arranged around the sensor part for attaching the measurement sensor to the object having the measurement target and for supporting the sensor part.
Especially, accomplishing monitoring and control of operation in a modern reciprocating engine demands a number of measurement sensors arranged in the engine. Often, the distance between the attachment point and the measurement point varies as the application locations of the measurement sensor are changed. It would naturally be preferable to be able to construct the sensors externally as similar as possible regardless of the object of measurement. However, in the various measurement places of an engine there often are differences in distance between the mounting point of the sensor and the measurement point and additionally, the distance of the sensor itself from the point to be measured can be different. Further, during operation there might be a need to adjust this distance.
The object of the invention is to produce a measurement sensor, by means of which the distance between the mounting point of the sensor and the measurement point can be adjusted and set easily and accurately and that also maintains the set distance in a demanding environment.
The objects of the invention are mainly achieved as disclosed in the appended claim 1 and as more closely explained in other claims.
The measurement sensor according to the invention comprises an elongated sensor part, at the first end of which the electrical connection of the sensor part is located and at the second end of which the sensor end of the sensor part is
located. The measurement sensor comprises a first sleeve part arranged around a sensor part for attaching a measurement sensor to the object to be measured and for supporting the sensor part. A characterising feature of the invention is that the measurement sensor comprises a second sleeve part rotatably arranged inside the first sleeve part and that the sensor part comprises an outer screw thread and the second sleeve part comprises an internal screw thread, the outer thread of the sensor part and the inner thread of the second sleeve part being attached to each other so that when the second sleeve part is rotated in relation to the sensor part, the sensor part moves in the direction of its longitudinal axis in relation to the first and second sleeve parts. Thus, the position of the sensor part can be adjusted without turning the sensor part itself.
In more detail, the measurement sensor according to one preferable embodiment comprises the second sleeve part to extend to a first direction inside a first sleeve part, the second sleeve part being rotatably arranged in connection with the first sleeve part, the measurement sensor comprising a third sleeve part to extend in another direction inside the first sleeve part, the third sleeve part being rotatably arranged inside the first sleeve part. The second and third sleeve parts are positioned in the measurement sensor in power transmission connection with each other so that the second sleeve part rotates as the third sleeve part is rotated and that the sensor part comprises an external thread and the second sleeve part comprises an internal thread, the external thread of the sensor part and the internal thread of the second sleeve part are in mesh with each other.
The measurement sensor additionally comprises a locking nut arranged on the external thread of the sensor part on the side of the first end of the sensor part of the first sleeve part. The second sleeve part is wholly arranged inside the first sleeve part and it is locked by means of a locking nut acting axially as a locking part.
Either one of the second or third sleeve parts comprises at least one recess and the other an extension fitting into the recess, respectively, by means of which the power transmission connection of these is carried out. The length of the recess in
the axial direction of the measurement sensor is longer than the axial length of the extension corresponding with it, whereby during installation the tightening of the locking screw pushes the second and third sleeve parts into the first sleeve part and thereby locks the parts of the measurement sensor into each other.
In the following the invention is described by way of example and with reference to the appended drawings, of which figure 1 shows an embodiment according to the invention in cross-section, figure 2 illustrates the embodiment of figure 1 with the parts disassembled from each other, and figure 3 illustrates another embodiment according to the invention.
Figures 1 and 2 show an embodiment of the measurement sensor 1 according the invention. It consists of a sensor part 3, the part being a mainly cylindrical piece having an elongated shape. The first end 3.1 of the sensor part contains its electrical connection 3.2, to which the cabling attached thereto is connected. The sensor of the sensor part is accordingly located in the other end, the sensor end 3.3. The sensor part can also be provided with various types of sensors depending on each application. The measurement sensor comprises a first sleeve part 2, by which the measurement part 3 of the measurement sensor 1 is supported and through which the measurement sensor is further attached to the object to be measured. The first sleeve part 2 comprises a first end 2.1 and a second end 2.2. The first end 2.1 is provided with an external thread 2.3 for attaching the first sleeve part to the object to be measured, whereas the second end 2.2 is formed as a hexagonal nut for ease of attaching.
Inside the first sleeve part 2 is arranged a second sleeve part 4 freely rotatable around its longitudinal axis. The second sleeve part comprises a collar preventing the second sleeve part to fully move through the first sleeve part 2. The collar is located on the side of the first end 2.1 of the first sleeve part. The second sleeve part 4 is provided with an internal thread 4.1 , the purpose of which is described in the following. Namely, the sensor part 3 of the measurement sensor 1 is provided
with an external thread 3.3, corresponding to the internal thread 4.1 of the second sleeve part. By means of this, the sensor part 3 is threaded into the thread 4.1 of the second sleeve part 4, whereby the sensor part is supported by the first sleeve part via the second sleeve part. According to the basic idea of the invention, when the sensor part is prevented from rotating and the second sleeve part 4 is rotated, the sensor part moves in the direction of the longitudinal axis in relation to the first and second sleeve parts. Thus, the position of the sensor part of the measurement sensor in relation to the object to be measured and also to the attachment point of the measurement sensor can be adjusted simply by rotating the second sleeve part. This solution keeps the sensor part 3 from rotating, whereby there will be no turning of the cabling, either. This will also avoid having to remove the cabling, which would be necessary if the cabling rotated when installing or adjusting the sensor.
In order to rotate the second sleeve part 4, in the embodiments of the figures a third sleeve part 5 has been further rotatably arranged inside the first sleeve part. The third sleeve part also comprises a collar preventing the third sleeve part to wholly move through the first sleeve part 2. The collar is located on the side of the second end 2.1 of the first sleeve part. The second and third sleeve parts are in connection with each other so the rotating the third sleeve part also causes the rotation of the second sleeve part. Thus, when the measurement sensor is installed, for example, an opening made in a wall, the measurement sensor can be moved without the need for access to the measurement sensor on the other side of the wall.
Figure 2 illustrates, how, among others, the second sleeve part 4 is provided with two recesses 4.1 on the circumference forming its second end. The third sleeve part is correspondingly provided with extensions 5.1 that can be located in the recesses 4.1. When the second and third sleeve parts are installed inside the first sleeve part, the extensions 5.1 set into the recesses 4.1 , whereby the power needed for rotating the second sleeve part 4 is transmitted through the pairs of extensions and recesses from the third sleeve part 5. Such a power transmission connection can be accomplished using a similar principle with solutions having
different details. It is important that it be possible to rotate the second sleeve part 4 from the side of the second end 2.2 of the first sleeve part.
A locking nut 6 has been arranged on the thread of the sensor part 3, by means of which the assembly can be locked to place subsequent to adjustment. When the locking nut 6 is tightened, the first sleeve part 5 is pushed between the collar 4 of the second sleeve part and the collar of the third sleeve part, whereby the assembly is locked in its place.
Figure 3 illustrates an embodiment in which the second sleeve part 4 extends out from the second end 2.2 of the first sleeve part 2, whereby it can be rotated directly without a separate intermediate piece as shown in the embodiment of figure 1. In the embodiment of figure 3 the locking nut 6 is also slightly different in shape from that in figure 1. This is because the tightening force of the locking nut is here directed directly against the first sleeve part 2.
The invention is not limited to the embodiments described here, but a number of modifications thereof can be conceived of within the scope of the appended claims.