Ultrasonic transmission and reception system

Abstract

This system provides an ultrasonic transmission and reception system that identifies the connection status of the connecting cable on the measurement unit side and performs ultrasonic transmission and reception control according to the identified connection status. [Solution] The measurement unit 20 includes a transmitting circuit 31 that transmits a drive signal to ultrasonic transmitting and receiving elements 11d and 12d, a receiving circuit 32 that receives measurement signals from ultrasonic transmitting and receiving elements 12d and 11d, a control unit 33 that communicates with the electronic device unit 11g, and first, second, and third switch units 40, 50, and 60. The control unit 33 can identify one of the pair of second connecting wires 21c and 22c connected to the ultrasonic transmitting and receiving element 11d in response to a response signal from the electronic device unit 11g. After identification, the control unit 33 starts switching control of each switch unit according to the connection state, and transmit and receive control of the transmitting circuit 31 and the receiving circuit 32.

Description

Technical Field

[0001] The present invention relates to an ultrasonic transmission / reception system that identifies the connection state of a connection cable between a detection unit and a measurement unit and performs ultrasonic transmission / reception control according to the identified connection state.

Background Art

[0002] Patent Document 1 discloses an ultrasonic flowmeter connected to a pair of ultrasonic sensor elements of a detection unit that detects flow rate or the like via a coaxial cable. In an ultrasonic flowmeter widely used like the ultrasonic flowmeter disclosed in Patent Document 1, a connector is attached to the connection cable and is detachably connected to a detection unit provided with ultrasonic sensor elements or an ultrasonic flowmeter.

[0003] In such an ultrasonic flowmeter, the pair of connection cables may be reversely connected to the detection unit. Even in such a reversely connected state, the ultrasonic flowmeter can acquire measurement data from the ultrasonic sensor elements of the detection unit, but it cannot measure the accurate flow velocity and flow rate of the fluid flowing in the measurement pipe.

[0004] Therefore, elements visually distinguishable such as colors or labels are added to the connector cable, or the types, male and female, and shapes of the connection ports of the connectors are made different for each connector to prevent incorrect connection.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when adding the aforementioned identifiable elements, workers must work carefully, and in some cases, the problem arises that workers may mistakenly add identifiable elements incorrectly.

[0007] Furthermore, if the connector types, male / female configurations, and connection port shapes differ for each connector, it becomes necessary to have male and female connectors with different external shapes. This leads to the problem of complicated management of numerous connectors and increased manufacturing costs.

[0008] The object of the present invention is to solve the above-mentioned problems and provide an ultrasonic transmitting and receiving system that identifies the connection status of a connecting cable on the measurement unit side, regardless of the connection status of the connecting cable, and performs control according to the identified connection status. [Means for solving the problem]

[0009] The ultrasonic transmitting and receiving system according to the present invention for achieving the above objective comprises a pair of ultrasonic transmitting and receiving elements, a detection unit having an engaged portion or engaging portion connected to each of the pair of ultrasonic transmitting and receiving elements via a first connecting wire, and a measurement unit having the engaged portion or a pair of engaging portions that engage with the engaging portion, and connected to the detection unit via a pair of connecting cables, wherein the measurement unit includes a transmitting circuit that transmits a drive signal to one or the other of the ultrasonic transmitting and receiving elements, a receiving circuit that receives a measurement signal from the other or one of the ultrasonic transmitting and receiving elements, and the pair of connecting cables An ultrasonic transmitting and receiving system comprising a pair of switch units that switch between a contact point to which a pair of second connecting wires continuous with a bull are connected, and a contact point to which the transmitting circuit and the receiving circuit are connected, wherein an electronic device unit is provided near at least one of the ultrasonic transmitting and receiving elements, connected to a first branch wire that branches in parallel from the first connecting wire, and the measuring unit is provided with a control unit that communicates with the electronic device unit, and a switching connection unit that has one end connected to the control unit and the other end switchable to either of the pair of second connecting wires.

[0010] The ultrasonic transmitting and receiving system according to the present invention for achieving the above-mentioned objectives comprises a pair of ultrasonic transmitting and receiving elements, a detection unit having an engaged portion connected to each of the pair of ultrasonic transmitting and receiving elements via a first connecting wire, and a measurement unit connected to the detection unit via a pair of connecting cables having an engaged portion at each end that engages with the engaged portion, wherein the measurement unit comprises a transmitting circuit that transmits a drive signal to one or the other of the ultrasonic transmitting and receiving elements, a receiving circuit that receives a measurement signal from the other or one of the ultrasonic transmitting and receiving elements, a pair of switch units that switchably connect a pair of second connecting wires continuous with the pair of connecting cables and a pair of switch units that connect the transmitting circuit and the receiving circuit, wherein at least one of the ultrasonic transmitting and receiving elements is provided near the first ultrasonic transmitting and receiving element, connected to a first branch wire that branches in parallel from one of the first connecting wires, and the measurement unit is provided with a control unit that communicates with the first electronic device unit, and a connection unit that has one end connected to the control unit and the other end connected to one of the second connecting wires. [Effects of the Invention]

[0011] According to the ultrasonic transmitting and receiving system of the present invention, an electronic device is provided via a branch wire to at least the first connecting wire connected to the ultrasonic transmitting and receiving elements of the detection unit, and a control unit that communicates with the electronic device is provided in the measurement unit connected to the detection unit, so that the measurement unit can identify one of the pair of second connecting wires connected to the ultrasonic transmitting and receiving elements. After identifying the connection state, the control unit starts switching control of each switch unit according to the connection state, and transmit and receive control of the transmitting circuit and the receiving circuit, thereby enabling accurate measurement data between the pair of ultrasonic transmitting and receiving elements from the detection unit. [Brief explanation of the drawing]

[0012] [Figure 1] This is a block circuit diagram of the ultrasonic transmitting and receiving system of Example 1. [Figure 2]It is a block circuit configuration diagram of an ultrasonic transmission and reception system with a connection state opposite to that in FIG. 1. [Figure 3] It is a flowchart diagram of the control unit. [Figure 4] It is a timing chart diagram in the connection state of FIG. 1. [Figure 5] It is a timing chart diagram in the connection state of FIG. 2. [Figure 6] It is a block circuit configuration diagram of the ultrasonic transmission and reception system of Example 2. [Figure 7] It is a timing chart diagram in the case of forward connection. [Figure 8] It is a block circuit configuration diagram of the ultrasonic transmission and reception system of Example 3. [Figure 9] It is a flowchart diagram of the control unit. [Figure 10] It is a timing chart diagram in the case of forward connection. [Figure 11] It is a timing chart diagram in the case of reverse connection. [Figure 12] It is a block circuit configuration diagram of the transmission and reception control unit of Example 4. [Figure 13] It is a timing chart diagram in the case of forward connection. [Figure 14] It is a flowchart diagram of the control unit. <00000​​​​​​​​​​​​​​​​The ultrasonic flowmeter is composed of a detection unit 10 provided with a pair of ultrasonic transceiver elements arranged opposite to each other at both ends of a straight pipeline through which a fluid flows, and a measurement unit 20 connected to these ultrasonic transceiver elements via a coaxial cable.

[0016] The pipeline 10a of the detection unit 10 is made of a synthetic resin material such as polypropylene or Teflon (registered trademark). Near both ends of the straight pipeline 10b, an inlet pipeline 10c for introducing fluid in a direction perpendicular to the axial direction of the straight pipeline 10b and an outlet pipeline 10d for discharging fluid are arranged in a so-called crank type.

[0017] The straight pipeline 10b, the inlet pipeline 10c, and the outlet pipeline 10d that constitute the pipeline 10a have an inner diameter of, for example, 4 mm. At each end of the inlet pipeline 10c and the outlet pipeline 10d, connection ports (not shown) are formed from a synthetic resin material connected to a pump, etc., so that a flexible pipe can be easily connected and is difficult to come off.

[0018] Note that the inlet pipeline 10c and the outlet pipeline 10d may be configured to have the same shape as shown in FIG. 1, for example, or the shape can be appropriately changed according to the installation space of the detection unit 10.

[0019] Also, although the pipeline 10a is arranged in a crank type in FIG. 1, any appropriate shape can be adopted as long as it is a pipeline shape in which a pair of ultrasonic transceiver elements are arranged opposite to each other across the pipeline through which the fluid flows. <000011​​​​​​​

[0022] In these gaps, ultrasonic transmitting and receiving elements 11d and 12d, which are in close contact with the wall surfaces 11a and 12a and transmit and receive ultrasonic waves to and from the straight pipe 10b, and first connecting wires 11e and 12e, which are drawn out from the ultrasonic transmitting and receiving elements 11d and 12d, are respectively arranged. By applying a voltage to the ultrasonic transmitting and receiving elements 11d and 12d, which are made of piezoelectric transducers, an ultrasonic beam is propagated into the fluid in the straight pipe 10b.

[0023] On the outer surfaces of the inlet-side transmitting / receiving unit 11 and the outlet-side transmitting / receiving unit 12, there are engaged parts 11f and 12f, respectively, one of which is connected to the first connecting wires 11e and 12e, and the other of which can engage with the engaging parts 21a and 22a to which the measuring unit 20 is connected.

[0024] The engaging parts 21a and 22a are connector bodies of the same shape, and the engaged parts 11f and 12f are socket bodies of the same shape. The locations where the engaged parts 11f and 12f are provided can be placed at any appropriate location near the ultrasonic transmitting and receiving elements 11d and 12d, and furthermore, the engaging parts and engaged parts of the same shape may be provided on the measuring unit 20 side. In such cases, the first connecting wires 11e and 12e will be directly connected to the connecting cable consisting of a coaxial cable.

[0025] Furthermore, an electronic device unit 11g is installed inside the air gap of the inlet-side transmitting / receiving unit 11. This electronic device unit 11g is connected to a branch wire 11h, which is branched in parallel from the first connecting wire 11e, via a protection circuit unit (not shown). This protection circuit unit suppresses overvoltage and overcurrent applied to the electronic device unit 11g in the event of a malfunction, and employs a well-known protection circuit.

[0026] Furthermore, the electronic device section 11g, located near the ultrasonic transmitting / receiving element 11d, is, for example, a memory chip made of a semiconductor memory element that serves as a storage medium, and is capable of communicating with a control unit, including a device communication circuit described later.

[0027] A pair of connecting cables 21b and 22b, consisting of coaxial cables with an outer surface covering, are wired from the housing to the measuring unit 20, and the aforementioned engaging parts 21a and 22a are attached to the ends of these connecting cables 21b and 22b.

[0028] Furthermore, the measurement unit 20 is provided with a transmitting circuit 31 that transmits a drive signal to the ultrasonic transmitting / receiving element 11d or ultrasonic transmitting / receiving element 12d, a receiving circuit 32 that receives a measurement signal from the ultrasonic transmitting / receiving element 12d or ultrasonic transmitting / receiving element 11d, a control unit 33 that communicates with the electronic device unit 11g, a first switch unit 40 that connects a common contact to the transmitting circuit 31 and allows the contacts of a pair of second connecting wires 21c and 22c, which are continuous with a pair of connecting cables 21b and 22b, to be switched as the connection destination of the common contact of the transmitting circuit 31, a second switch unit 50 that connects a common contact to the receiving circuit 32 and allows the contacts of the second connecting wires 21c and 22c to be switched as the connection destination of the common contact of the receiving circuit 32, and a third switch unit 60 that connects a common contact to the control unit 33 and allows the contacts of the second connecting wires 21c and 22c to be switched as the connection destination of the common contact of the control unit 33.

[0029] The control unit 33, consisting of a CPU and the like, performs communication with the electronic device unit 11g, as well as switching control of the first, second, and third switch units 40, 50, and 60, and transmission and reception control of the transmission circuit 31 and the reception circuit 32. Note that the communication processing of the electronic device unit 11g and other processing may be performed by different processing units.

[0030] The first switch unit 40 includes a first contact 41 which is connected to one of the second connecting wires 21c, a second contact 42 which is connected to a branch wire 22d that branches off from the other second connecting wire 22c, and a common contact 43 which is connected to the transmission circuit 31.

[0031] Similarly, the second switch unit 50 includes a first contact 51 which is connected to the other second connecting wire 22c, a second contact 52 which is connected to a branch wire 21d that branches off from one of the second connecting wires 21c, and a common contact 53 which is connected to the receiving circuit 32.

[0032] Furthermore, the third switch unit 60 includes a first contact 61 which is connected to a branch wire 21e branching off from one of the second connecting wires 21c, a second contact 62 which is connected to a branch wire 22e branching off from the other second connecting wire 22c, and a common contact 63 which is connected to the control unit 33.

[0033] Furthermore, as shown in the diagram, the connection destination of these first, second, and third switch units 40, 50, and 60 can all be changed by appropriately switching the movable contacts that are continuous with the common contacts 43, 53, and 63.

[0034] Figure 3 is a flowchart of the control unit 33, and when power is applied to the measurement unit 20, the process proceeds to step ST11. The first, second, and third switch units 40, 50, and 60 of the measurement unit 20 are connected to the first contacts 41, 51, and 61, respectively, at startup.

[0035] In the third switch section 60, the first contact 61 and the common contact 63 are connected, and the engaging section 21a is connected via the second connecting wire 21c and connecting cable 21b to either the engaged section 11f, which is in the connected state shown in Figure 1, or the engaged section 12f, which is in the connected state shown in Figure 2.

[0036] In step ST11, it is determined whether or not there is a response from the electronic device unit 11g. If the engaging unit 21a is connected to the engaged unit 11f shown in Figure 1 and a response is received from the electronic device unit 11g, the process proceeds to step ST12.

[0037] In step ST12, the control unit 33 starts switching control of the first and second switch units 40 and 50 in accordance with the forward connection switching control, and starts transmitting and receiving control of the transmitting circuit 31 and the receiving circuit 32.

[0038] Figure 4 is a timing chart diagram for the sequential connection state shown in Figure 1. As described above, when device communication is performed with the electronic device unit 11g in steps ST11 and ST12, the first contacts 41 and 51 are connected to the common contacts 43 and 53, the output destination of the drive signal of the transmission circuit 31 is the ultrasonic transmitting / receiving element 11d, and the input source of the measurement signal of the receiving circuit 32 is the ultrasonic transmitting / receiving element 12d, and this is processed by the control unit 33.

[0039] Furthermore, when the first contacts 41, 51 of the first and second switch sections 40, 50 are switched to the second contacts 42, 52, and the second contacts 42, 52 are connected to the common contacts 43, 53, the output destination of the drive signal of the transmitting circuit 31 is treated as the ultrasonic transmitting / receiving element 12d, and the input source of the measurement signal of the receiving circuit 32 is treated as the ultrasonic transmitting / receiving element 11d.

[0040] In this way, the control unit 33 repeatedly transmits a drive signal by the transmitting circuit 31 and receives a measurement signal by the receiving circuit 32, and in response, the ultrasonic transmitting and receiving elements 11d and 12d alternately transmit and receive ultrasonic beams in accordance with the switching control of the first and second switch units 40 and 50.

[0041] Based on these processes, the control unit 33 can calculate the fluid velocity and flow rate in the straight pipe 10b. The procedure for this calculation is as follows: First, the ultrasonic beam emitted from the upstream ultrasonic transmitting / receiving element 11d propagates through the fluid in the straight pipe 10b and reaches the downstream ultrasonic transmitting / receiving element 12d. Next, the ultrasonic beam emitted from the downstream ultrasonic transmitting / receiving element 12d enters the straight pipe 10b and reaches the upstream ultrasonic transmitting / receiving element 11d.

[0042] The propagation speed of the ultrasonic beam from ultrasonic transmitting / receiving element 11d to ultrasonic transmitting / receiving element 12d in the fluid is accelerated by the fluid flowing in the direction of the arrow from the inlet pipe 10c to the outlet pipe 10d in Figure 1, while the propagation speed of the ultrasonic beam from ultrasonic transmitting / receiving element 12d to ultrasonic transmitting / receiving element 11d is decelerated because it is moving in the opposite direction to the flow direction.

[0043] In the control unit 33, by determining the difference in arrival time of the ultrasonic beam measurement signals obtained by transmitting and receiving in these two directions, the fluid velocity in the straight pipe 10b can be measured using a known measurement method, and the flow rate can be calculated by multiplying this by the cross-sectional area of ​​the straight pipe 10b.

[0044] In step ST11, if the control unit 33 does not receive a response signal from the electronic device unit 11g, it proceeds to step ST13, switches the connection destination of the common contact 63 of the third switch unit 60 from the first contact 61 to the second contact 62, and proceeds to step ST14.

[0045] If no response signal is received from the electronic device unit 11g in step ST11, it can be inferred that the connection state is not as shown in Figure 1, but as shown in Figure 2.

[0046] In step ST14, similar to step ST11, it is determined whether or not there is a response from the electronic device unit 11g. If a response signal is received from the electronic device unit 11g, the process proceeds to step ST15.

[0047] In step ST15, the control unit 33 starts switching control of the first and second switch units 40 and 50 according to the reverse connection, and starts transmitting and receiving control of the transmitting circuit 31 and the receiving circuit 32.

[0048] Figure 5 is a timing chart diagram for the reverse connection state shown in Figure 2. As shown, when the common contact 63 of the third switch unit 60 is connected to the second contact 62, switching control is performed to alternately switch the first contacts 41, 51 and the second contacts 42, 52 of the first and second switch units 40, 50 at the switching timing for the switch unit that is the opposite of the forward connection, upon receiving a response signal from the electronic device unit 11g.

[0049] In such a reverse connection, when the second contacts 42 and 52 are connected to the common contacts 43 and 53, the output destination of the drive signal of the transmitting circuit 31 is the ultrasonic transmitting / receiving element 11d, and the input source of the measurement signal of the receiving circuit 32 is the ultrasonic transmitting / receiving element 12d, and this is processed by the control unit 33.

[0050] Furthermore, when the first contacts 41 and 51 are connected to the common contacts 43 and 53, the output destination of the drive signal of the transmitting circuit 31 is treated as the ultrasonic transmitting / receiving element 12d, and the input source of the measurement signal of the receiving circuit 32 is treated as the ultrasonic transmitting / receiving element 11d.

[0051] If there is no response from the electronic device unit 11g in step ST14, the process proceeds to step ST16, where a malfunction occurs in the detection unit 10, measurement unit 20, etc., such as damage to the electronic device unit 11g or a break in the connecting cables 21b and 22b, and processing is performed to indicate that a malfunction has occurred. This processing is notified externally, for example, by generating an alarm sound or flashing a display on the monitor. [Examples]

[0052] Figure 6 is a block circuit diagram of the ultrasonic transmitting and receiving system of Example 2, and Figure 7 is a timing chart diagram of the connection shown in Figure 6. One difference between Example 1 and Example 2 is that the common contacts 44' and 54' of the first and second switch sections 40' and 50' are located on the second connecting wire 21c and 22c side.

[0053] The first switch unit 40' consists of a first contact 41' connected to the transmitting circuit 31, a second contact 42' connected to the receiving circuit 32, a third contact 43' connected to the control unit 33, and a common contact 44' connected to the second connecting electrical equipment 21c.

[0054] The second switch section 50' consists of a first contact 51' connected to the transmitting circuit 31, a second contact 52' connected to the receiving circuit 32, a third contact 53' connected to the control unit 33, and a common contact 54' connected to the second connecting electrical equipment 22c.

[0055] The transmitting circuit 31, the receiving circuit 32, and the control unit 33 are all connected to the first and second switch units 40' and 50' respectively via the main line and branch lines branching off from the main line, and switching control is performed so that the two contacts at the branch destinations are not connected to the common contacts 44' and 54' at the same time.

[0056] As shown in the timing chart in Figure 7, first the common contact 44' of the first switch section 40' and the third contact 43' are connected, and at the same time the common contact 54' of the second switch section 50' and the first contact 51' are connected.

[0057] After connection, the control unit 33 performs the same process as in step ST11 in Figure 3. When it receives a response signal from the electronic device unit 11g, it performs the forward connection process in Embodiment 1, that is, the process of switching the first contacts 41, 51 and the second contacts 42, 52 alternately in synchronization with each other, for the first contacts 41', 51' and the second contacts 42', 52'. In this way, the control unit 33 in Embodiment 2 starts switching control of the first and second switch units 40', 50' according to the forward connection, and transmit / receive control of the transmit circuit 31 and the receive circuit 32.

[0058] Furthermore, if no response signal is received from the electronic device unit 11g, the first switch unit 40' switches from the third contact 43' to the first contact 41', and at the same time, the second switch unit 50' switches from the first contact 51' to the third contact 53'.

[0059] This process is the same as the process in step ST13 in Figure 3, and this switching process switches the connection destination of the control unit 33 from one second connecting wire 21c to the other second connecting wire 22c.

[0060] When a response signal is received from the electronic device unit 12g in this connection state, although the timing chart diagram is not shown, the control unit 33 in Embodiment 2 starts switching control of the first and second switch units 40' and 50', and transmit / receive control of the transmit circuit 31 and receive circuit 32, similar to the reverse connection switching control in Embodiment 1.

[0061] Furthermore, even after switching from the first contact 51' to the third contact 53' of the second switch unit 50', if there is no response from the electronic device unit 11g, it is determined that a malfunction has occurred as described above, and this is notified externally.

[0062] Thus, in both Embodiments 1 and 2, the measuring unit 20 is provided with a pair of first switch units 40, 40' and second switch units 50, 50' that switchably connect the contacts to which a pair of second connecting wires 21c, 22c are connected to the contacts to which the transmitting circuit 31 and the receiving circuit 32 are connected.

[0063] Furthermore, in the ultrasonic transmitting and receiving systems of Examples 1 and 2, the measuring unit 20 is provided with a switching connection section that allows one end to be connected to the control unit 33 and the other end to be switchedly connected to either of the pair of second connecting wires 21c and 22c.

[0064] Furthermore, the switching connection section in Embodiment 1 is a third switch section 60 including first and second contacts 61 and 62, while the switching connection section in Embodiment 2 is provided within the first and second switch sections 40' and 50' respectively, and is a third contact 43' and 53' that connects to a control unit 33 that can be switched between a common contact 44' and 54' of a pair of second connecting wires 21c and 22c. [Examples]

[0065] Figure 8 is a block circuit diagram of the ultrasonic transmitting and receiving system of Embodiment 3. The differences between Embodiment 1 and Embodiment 3 are that the measurement unit 20 does not have a third switch unit 60, and in addition to the electronic device unit 11g being installed inside the air gap of the inlet side transmitting and receiving unit 11, an electronic device unit 12g is also installed inside the air gap of the outlet side transmitting and receiving unit 12. This electronic device unit 12g is connected to a branch wire 12h that is branched in parallel from the first connecting wire 12e via a protection circuit unit (not shown).

[0066] The control unit 33 is connected only to the branch wire 21e that branches off from one of the second connecting wires 21c, and it is possible to identify the electronic device units 11g and 12g from the difference in the response signals from the electronic device units 11g and 12g to which it is connected.

[0067] Figure 9 is a flowchart of the control unit 33, and when power is applied to the measurement unit 20, the process proceeds to step ST21. The first and second switch units 40 and 50 of the measurement unit 20 are connected to the first contacts 41 and 51, respectively, at startup.

[0068] The engaging portion 21a is connected to either the engaged portion 11f or the engaged portion 12f, which are in the connected state shown in Figure 9, via the second connecting wire 21c and connecting cable 21b. When the engaging portion 21a is connected to the engaged portion 11f or the engaged portion 12f, the control unit 33 becomes capable of communicating with the electronic device portion 11g or the electronic device portion 12g.

[0069] In step ST21, it is determined whether or not there is a response from the electronic device unit 11g. If the engaging unit 21a is connected to the engaged unit 11f shown in Figure 9 and a response is received from the electronic device unit 11g, the process proceeds to step ST22.

[0070] In step ST22, the control unit 33 starts switching control of the first and second switch units 40 and 50 in the sequential connection shown in the timing chart diagram of Figure 10, and transmit / receive control of the transmit circuit 31 and the receive circuit 32.

[0071] If no response signal is received from the electronic device unit 11g in step ST21, the process proceeds to step ST23 to determine whether or not there is a response from the electronic device unit 12g.

[0072] If a response is received from the electronic device unit 12g in step ST23, the process proceeds to step ST24. In step ST23, the control unit 33 starts switching control of the first and second switch units 40 and 50 in reverse connection as shown in the timing chart diagram of Figure 11, and transmit / receive control of the transmit circuit 31 and the receive circuit 32. [Examples]

[0073] Figure 12 is a block circuit diagram of the ultrasonic transmitting and receiving system of Example 4. The differences between Example 2 and Example 4 are that the second switch section 50' of the measuring section 20 does not have a third contact 53', and the electronic device section 12g is installed inside the air gap of the outlet side transmitting and receiving section 12.

[0074] The control unit 33 is connected only to the third contact 43' of the first switch unit 40'. By connecting the common contact 44', which is connected to the second connecting wire 21c, to the third contact 43', it is possible to identify the electronic device units 11g and 12g based on the difference in the response signals from the electronic device units 11g and 12g to which the connection is made.

[0075] In Embodiment 4, when power is applied to the measuring unit 20, the common contact 44' of the first switch unit 40' and the third contact 43' are connected first, and at the same time, the common contact 54' of the second switch unit 50' and the first contact 51' are connected.

[0076] The engaging portion 21a is connected to either the engaged portion 11f or the engaged portion 12f, which is in the connected state shown in Figure 12, via the second connecting wire 21c and connecting cable 21b.

[0077] Then, when the engaging portion 21a engages with the engaged portion 11f and a response signal is received from the electronic device portion 11g, the first contacts 41', 51' and the second contacts 42', 52' are switched in sync, and the transmitting and receiving control of the transmitting circuit 31 and the receiving circuit 32 is started, similar to the switching control of the first and second switch portions 40, 50 in reverse connection as shown in the timing chart diagram of Figure 11.

[0078] Thus, in both Embodiments 3 and 4, the measuring unit 20 is provided with a pair of first switch units 40, 40' and second switch units 50, 50' that switchably connect the contacts to which a pair of second connecting wires 21c, 22c are connected to the contacts to which the transmitting circuit 31 and the receiving circuit 32 are connected.

[0079] Furthermore, in Examples 3 and 4, the measuring unit 20 is provided with a connection part that connects one end to the control unit 33 which communicates with the electronic device unit 11g or the electronic device unit 12g, and the other end to one of the second connecting wires 21c.

[0080] Furthermore, the aforementioned connection in Embodiment 3 is a branch wire 21e that branches off from one of the second connecting wires 21c and connects to the control unit 33, while the aforementioned connection in Embodiment 4 is provided within the first switch section 40' and indicates a third contact 43' that is switchable and connects to the control unit 33, which is connected to the common contact 44' of one of the second connecting wires 21c.

[0081] In Examples 3 and 4, the electronic device unit 12g is installed inside the gap of the output-side transmitting / receiving unit 12, but this is not always necessary. Figure 14 is a flowchart of the control unit 33 in Examples 3 and 4 when specifying the connection status of a simplified connection cable in which the electronic device unit 12g is not installed inside the output-side transmitting / receiving unit 12.

[0082] When power is applied to the measurement unit 20, the process moves to step ST31, in which step ST31 determines whether or not there is a response from the electronic device unit 11g. If a response is received from the electronic device unit 11g, the process moves to step ST32, in which the control unit 33 starts switching control of the first and second switch units 40 and 50 in sequential connection, and transmit / receive control of the transmit circuit 31 and the receive circuit 32.

[0083] If no response is received from the electronic device unit 11g in step ST31, the process proceeds to step ST33, where the control unit 33 starts switching control of the first and second switch units 40 and 50 in the case of reverse connection, and transmit / receive control of the transmit circuit 31 and the receive circuit 32.

[0084] As described above, with the ultrasonic transmitting and receiving system according to the present invention, an electronic device unit 11g is provided via a branch wire 11h to at least the first connecting wire 11e connected to the ultrasonic transmitting and receiving element 11d of the detection unit 10, and a control unit 33 that communicates with the electronic device unit 11g is provided in the measurement unit 20 connected to the detection unit 10, so that the measurement unit 20 can identify which of the pair of second connecting wires 21c and 22c connected to the ultrasonic transmitting and receiving element 11d is the electronic device unit 11g.

[0085] After identifying the connection status, the control unit 33 starts switching control of each switch section according to the connection status, and transmit / receive control of the transmit circuit 31 and the receive circuit 32, thereby enabling accurate measurement data to be obtained between the pair of ultrasonic transmitting and receiving elements 11d and 12d from the detection unit 10. [Explanation of Symbols]

[0086] 10 Detection unit 11d, 12d ultrasonic transmitting and receiving elements 11e, 12e First connecting wire 11f, 12f Engaged part 11g, 12g Electronic device section 11h, 12h, 21d, 21e, 22d, 22e Branch wires 20 Measuring part 21a, 22a engaging part 21b, 22b connection cable 21c, 22c Second connecting wire 31 Transmitter Circuit 32 Receiving Circuit 33 Control Unit 40, 40' First switch section 41, 41', 51, 51', 61 First point of contact 42, 42', 52, 52', 62 Second point of contact 43', 53' Third point of contact 43, 44', 53, 54', 63 Common contact points 50, 50' Second switch section 60 Third switch section

Claims

1. A detection unit comprising a pair of ultrasonic transmitting and receiving elements, and a engaged portion or engaging portion connected to each of the pair of ultrasonic transmitting and receiving elements via a first connecting wire, The unit comprises a measuring unit which is connected to the detection unit via a pair of connecting cables, and which is provided with the engaged portion or a pair of engaged portions that engage with the engaged portion, The measurement unit is an ultrasonic transmitting and receiving system comprising: a transmitting circuit that transmits a drive signal to one or the other ultrasonic transmitting and receiving element; a receiving circuit that receives a measurement signal from the other or one of the ultrasonic transmitting and receiving elements; a pair of contacts that are the destinations for a pair of second connecting wires continuous with the pair of connecting cables; and a pair of switch units that switch and connect the contacts that are the destinations for the transmitting circuit and the receiving circuit. Near one of the ultrasonic transmitting and receiving elements, an electronic device section is provided that is connected to a first branch wire that branches in parallel from one of the first connecting wires. The ultrasonic transmitting and receiving system is characterized in that the measuring unit is provided with a control unit that communicates with the electronic device unit, and a switching connection unit that has one end connected to the control unit and the other end switchable to either of the pair of second connecting wires.

2. The pair of switch units comprises a first switch unit that connects a common contact to the transmitting circuit and allows the contacts of the pair of second connecting wires to be switched as the connection destination of the common contact in the transmitting circuit, and a second switch unit that connects a common contact to the receiving circuit and allows the contacts of the pair of second connecting wires to be switched as the connection destination of the common contact in the receiving circuit. The ultrasonic transmitting and receiving system according to claim 1, characterized in that the switching connection unit is a third switch unit that connects a common contact to the control unit and allows the contacts of the pair of second connecting wires to be switched as the connection destination of the common contact of the control unit.

3. The switch unit comprises a first switch unit that connects a common contact to one of the pair of second connecting wires, allowing the contacts of the transmitting circuit and the receiving circuit to be switched as the connection destination of the common contact on the one second connecting wire, and a second switch unit that connects the common contact to the other second connecting wire, allowing the contacts of the receiving circuit and the transmitting circuit to be switched as the connection destination of the common contact on the other second connecting wire. The ultrasonic transmitting and receiving system according to claim 1, characterized in that the switching connection section is provided in the first and second switch sections, respectively, and is capable of switching connection with the common contact of the pair of second connecting wires, and is a pair of contacts that connect to the control unit.

4. The ultrasonic transmitting and receiving system according to claim 2 or 3, characterized in that when the control unit receives a response signal from the electronic device unit when the first second connecting wire is connected by the switching connection unit, it determines that it is a forward connection and starts switching control of the switch unit and transmitting and receiving control of the transmitting circuit and the receiving circuit according to the forward connection.

5. The ultrasonic transmitting and receiving system according to claim 4, characterized in that, when the control unit does not receive a response signal from the electronic device unit when the first second connecting wire is connected by the switching connection unit, it switches the contacts of the switching connection unit, and when it receives a response signal from the electronic device unit, it determines that it is a reverse connection and starts switching control of the switch unit and transmission and reception control of the transmitting circuit and the receiving circuit according to the reverse connection.

6. The ultrasonic transmitting and receiving system according to claim 5, characterized in that the control unit performs a process to determine that a malfunction has occurred if it does not receive a response signal from the electronic device unit even after switching the contacts of the switching connection unit.

7. A detection unit comprising a pair of ultrasonic transmitting and receiving elements, and a engaged portion connected to each of the pair of ultrasonic transmitting and receiving elements via a first connecting wire, It consists of a measuring unit connected to the detection unit via a pair of connecting cables, each having an engaging portion at its end that engages with the engaged portion, The measurement unit is an ultrasonic transmitting and receiving system comprising: a transmitting circuit that transmits a drive signal to one or the other ultrasonic transmitting and receiving element; a receiving circuit that receives a measurement signal from the other or one of the ultrasonic transmitting and receiving elements; a pair of contacts that are the destinations for a pair of second connecting wires continuous with the pair of connecting cables; and a pair of switch units that switchably connect the contacts that are the destinations for the transmitting circuit and the receiving circuit. Near at least one of the ultrasonic transmitting and receiving elements, a first electronic device section is provided, connected to a first branch wire that branches in parallel from one of the first connecting wires. The ultrasonic transmitting and receiving system is characterized in that the measuring unit is provided with a control unit that communicates with the first electronic device unit, and a connection unit that has one end connected to the control unit and the other end connected to one of the second connecting wires.

8. The pair of switch units comprises a first switch unit that connects a common contact to the transmitting circuit and allows switching of the contacts of a pair of second connecting wires, which are continuous with the pair of connecting cables, as the connection destination of the common contact in the transmitting circuit; and a second switch unit that connects a common contact to the receiving circuit and allows switching of the contacts of the pair of second connecting wires as the connection destination of the common contact in the receiving circuit. The ultrasonic transmitting and receiving system according to claim 7, characterized in that the connection part is a branch wire that branches off from one of the second connecting wires and connects to the control unit.

9. The switch unit comprises a first switch unit that connects a common contact to one of a pair of second connecting wires continuous with the pair of connecting cables, and allows the contacts of the transmitting circuit and the receiving circuit to be switched as the connection destination of the common contact of the one second connecting wire, and a second switch unit that connects the common contact to the other second connecting wire, and allows the contacts of the receiving circuit and the transmitting circuit to be switched as the connection destination of the common contact of the other second connecting wire. The ultrasonic transmitting and receiving system according to claim 7, characterized in that the connecting portion is provided within the first switch portion and is a contact that can be switched and connected to the common contact of one of the second connecting wires and connects to the control unit.

10. The ultrasonic transmitting and receiving system according to claim 8 or 9, characterized in that the control unit determines that the connection is forward when it receives a response signal from the first electronic device unit, determines that the connection is reverse when it does not receive a response signal from the first electronic device unit, and starts switching control of the first and second switch units and transmitting and receiving control of the transmitting circuit and the receiving circuit according to the determined forward or reverse connection.

11. Near the other ultrasonic transmitting and receiving element, a second electronic device section is provided, connected to a first branch wire that branches in parallel from the other first connecting wire. When the control unit, which communicates with the first and second electronic device units, receives a response signal from the first electronic device unit, it determines that the connection is forward and starts switching control of the first and second switch units and transmission / reception control of the transmission circuit and the reception circuit according to the forward connection. The ultrasonic transmitting and receiving system according to claim 8 or 9, characterized in that when a response signal is received from the second electronic device unit, it is determined that the connection is reversed, and switching control of the first and second switch units and transmission / reception control of the transmitting circuit and the receiving circuit are initiated in accordance with the reverse connection.

12. The ultrasonic transmitting and receiving system according to claim 11, characterized in that the control unit performs a process to determine that a malfunction has occurred if it does not receive a response signal from the first and second electronic device units.

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